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Notes and sources

Every study, with a link

The clickable version of the Notes and Sources section at the back of each book: 848 references, grouped by book and chapter. DOI and PMID links open the original paper.

Cover of Is Your Skincare Worth the Money?

Vol. 10

Is Your Skincare Worth the Money?

Evidence last reviewed October 15, 2026

Ch. 1Is Your Skincare Worth the Money?7
  1. Daily sunscreen and skin aging Hughes MCB, Williams GM, Baker P, Green AC. Sunscreen and prevention of skin aging: a randomized trial. Ann Intern Med 2013;158(11):781–790. doi:10.7326/0003-4819-158-11-201306040-00002. PMID 23732711.
  2. Topical tretinoin for photoaging Sitohang IBS, Makes WI, Sandora N, Suryanegara J. Topical tretinoin for treating photoaging: a systematic review of randomized controlled trials. Int J Womens Dermatol 2022;8(1):e003. doi:10.1097/JW9.0000000000000003. PMID 35620028. PMC9112391.
  3. Tretinoin studied since the 1980s Weiss JS, Ellis CN, Headington JT, et al. Topical tretinoin improves photoaged skin: a double-blind vehicle-controlled study. JAMA 1988;259(4):527–532. Search PubMed
  4. Moisturizers for dryness and eczema van Zuuren EJ, Fedorowicz Z, Christensen R, Lavrijsen A, Arents BWM. Emollients and moisturisers for eczema. Cochrane Database Syst Rev 2017;2:CD012119. doi:10.1002/14651858.CD012119.pub2. PMID 28166390.
  5. Sunscreen price and protection Mundada M, Schneider J, Wei ML. Sunscreen costs in association with sun protective behaviors. JAMA Dermatol 2026;162(4):402–405. doi:10.1001/jamadermatol.2025.6150. Also: Xu S, Kwa M, Agarwal A, Rademaker A, Kundu RV. Sunscreen product performance and other determinants of consumer preferences. JAMA Dermatol 2016.
  6. Vehicle (base cream) effect Watson REB, Ogden S, Cotterell LF, et al. A cosmetic "anti-ageing" product improves photoaged skin: a double-blind, randomized controlled trial. Br J Dermatol 2009;161(2):419–426. Search PubMed
  7. Retinoids and pregnancy See Chapters 5 and 10.
Ch. 2What Does Your Skin Actually Do?8
  1. Epidermal turnover Weinstein GD, Van Scott EJ. Autoradiographic analysis of turnover times of normal and psoriatic epidermis. J Invest Dermatol 1965;45(4):257–262, PMID 5837896; age-related transit times from data by Kligman.
  2. The 500-dalton rule Bos JD, Meinardi MM. The 500 Dalton rule for the skin penetration of chemical compounds and drugs. Exp Dermatol 2000;9(3):165–169. PMID 10839713.
  3. Collagen and skin thickness after menopause Brincat M, et al. A study of the decrease of skin collagen content, skin thickness, and bone mass in the postmenopausal woman. Obstet Gynecol 1987. PMID 3120067.
  4. Sun and visible facial aging Flament F, Bazin R, Laquieze S, Rubert V, Simonpietri E, Piot B. Effect of the sun on visible clinical signs of aging in Caucasian skin. Clin Cosmet Investig Dermatol 2013;6:221–232. doi:10.2147/CCID.S44686. PMID 24101874. PMC3790843.
  5. Smoking, sun and twins Guyuron B, Rowe DJ, Weinfeld AB, et al. Factors contributing to the facial aging of identical twins. Plast Reconstr Surg 2009;123(4):1321–1331. PMID 19337100.
  6. Melanin as a filter Kaidbey KH, Agin PP, Sayre RM, Kligman AM. Photoprotection by melanin: a comparison of black and Caucasian skin. J Am Acad Dermatol 1979;1(3):249–260. doi:10.1016/s0190-9622(79)70018-170018-1). PMID 512075.
  7. Skin color and UV damage Fajuyigbe D, Young AR. The impact of skin colour on human photobiological responses. Pigment Cell Melanoma Res 2016. PMC5132026.
  8. Probiotic cosmetics Theodorou IM, Kapoukranidou D, Theodorou M, et al. Cosmeceuticals: a review of clinical studies claiming to contain specific, well-characterized strains of probiotics or postbiotics. Nutrients 2024;16(15):2526. doi:10.3390/nu16152526. PMC11314542.
Ch. 3Reading the Label and the Ad10
  1. "Hypoallergenic" claims US Food and Drug Administration. Hypoallergenic cosmetics (consumer information). Almay, Inc. v. Califano, US Court of Appeals for the D.C. Circuit, 1977.
  2. US cosmetics law US Food and Drug Administration. Modernization of Cosmetics Regulation Act of 2022 (MoCRA).
  3. EU claims rules Commission Regulation (EU) No 655/2013 laying down common criteria for the justification of claims used in relation to cosmetic products; Regulation (EC) No 1223/2009 on cosmetic products.
  4. Filters in beauty ads Advertising Standards Authority (UK). Rulings on Tanologist Tan (We Are Luxe Ltd) and Skinny Tan, February 2021.
  5. Ingredient list order Regulation (EC) No 1223/2009, Article 19; US Code of Federal Regulations, 21 CFR 701.3.
  6. Phenoxyethanol limit Regulation (EC) No 1223/2009, Annex V.
  7. Allergens in "natural" and "clean" products Young PA, Gui H, Bae GH. Prevalence of contact allergens in natural skin care products from US commercial retailers. JAMA Dermatol 2022 (published online September 14, 2022). PMC9475434.
  8. Fragrance as the leading cosmetic allergen Johansen JD. Fragrance contact allergy: a clinical review. Am J Clin Dermatol 2003;4(11):789–798. PMID 14572300. Systematic review of patch testing with cosmetics, 2024. PMC11334351.
  9. Parabens and breast cancer Darbre PD, Aljarrah A, Miller WR, et al. Concentrations of parabens in human breast tumours. J Appl Toxicol 2004;24(1):5–13. Scientific Committee on Consumer Products (SCCP), opinion on parabens and breast cancer, 2005; Scientific Committee on Consumer Safety (SCCS), opinions on parabens, 2010–2013. Search PubMed
  10. Methylisothiazolinone Commission Regulation (EU) 2016/1198.
Ch. 4Sunscreen: The Cheapest Anti-Aging Product13
  1. Skin aging Hughes et al. 2013 (see Chapter 1).
  2. Squamous cell carcinoma Green A, Williams G, Neale R, et al. Daily sunscreen application and betacarotene supplementation in prevention of basal-cell and squamous-cell carcinomas of the skin: a randomised controlled trial. Lancet 1999;354(9180):723–729. Search PubMed
  3. Melanoma Green AC, Williams GM, Logan V, Strutton GM. Reduced melanoma after regular sunscreen use: randomized trial follow-up. J Clin Oncol 2011;29(3):257–263. Search PubMed
  4. Sunscreen ingredients in the blood Matta MK, Zusterzeel R, Pilli NR, et al. JAMA 2019;321(21):2082–2091. Matta MK, Florian J, Zusterzeel R, et al. JAMA 2020;323(3):256–267.
  5. US sunscreen rules US Food and Drug Administration, proposed sunscreen rule (2019) and proposed order (2021); Final Administrative Order OTC000039 adding bemotrizinol, June 2026.
  6. Benzene recalls Johnson & Johnson voluntary recall of aerosol sunscreens, July 14, 2021.
  7. Oxybenzone and coral Downs CA, Kramarsky-Winter E, Segal R, et al. Toxicopathological effects of the sunscreen UV filter, oxybenzone (benzophenone-3), on coral planulae and cultured primary cells and its environmental contamination in Hawaii and the U.S. Virgin Islands. Arch Environ Contam Toxicol 2016;70(2):265–288. Search PubMed
  8. Vitamin D Neale RE, Khan SR, Lucas RM, et al. The effect of sunscreen on vitamin D: a review. Br J Dermatol 2019;181(5):907–915. doi:10.1111/bjd.17980. Passeron T, et al. Sunscreen photoprotection and vitamin D status. Br J Dermatol 2019;181(5):916–931.
  9. Application amount Ou-Yang H, Stanfield J, Cole C, Appa Y, Rigel D. High-SPF sunscreens (SPF ≥ 70) may provide ultraviolet protection above minimal recommended levels by adequately compensating for lower sunscreen user application amounts. J Am Acad Dermatol 2012;67(6):1220–1227. Search PubMed
  10. Skin of color Agbai ON, Buster K, Sanchez M, et al. Skin cancer and photoprotection in people of color: a review and recommendations for physicians and the public. J Am Acad Dermatol 2014;70(4):748–762. PMID 24485530. Systematic review of UV exposure and melanoma in skin of color, JAMA Dermatology 2021. PMID 33325988.
  11. Tinted sunscreen and melasma Castanedo-Cázares JP, Hernández-Blanco D, Carlos-Ortega B, Fuentes-Ahumada C, Torres-Álvarez B. Near-visible light and UV photoprotection in the treatment of melasma: a double-blind randomized trial. Photodermatol Photoimmunol Photomed 2014;30(1):35–42. PMID 24313385.
  12. Babies under 6 months US Food and Drug Administration; American Academy of Pediatrics, HealthyChildren.org.
  13. SPF, broad spectrum, water resistance, application American Academy of Dermatology public guidance; FDA sunscreen labeling rule (2011).
Ch. 5Retinoids: The Best Evidence After Sunscreen7
  1. Tretinoin Sitohang et al. 2022 (see Chapter 1).
  2. Retinol Kafi R, Kwak HSR, Schumacher WE, et al. Improvement of naturally aged skin with vitamin A (retinol). Arch Dermatol 2007;143(5):606–612. Search PubMed
  3. Adapalene and photoaging Bagatin E, Gonçalves HS, Sato M, Almeida LMC, Miot HA. Comparable efficacy of adapalene 0.3% gel and tretinoin 0.05% cream as treatment for cutaneous photoaging. Eur J Dermatol 2018;28(3):343–350. Search PubMed
  4. Cosmetic retinoids Milosheska D, Roškar R. Use of retinoids in topical antiaging treatments: a focused review of clinical evidence for conventional and nanoformulations. Adv Ther 2022. PMC9618501.
  5. Bakuchiol Dhaliwal S, Rybak I, Ellis SR, et al. Prospective, randomized, double-blind assessment of topical bakuchiol and retinol for facial photoageing. Br J Dermatol 2019;180(2):289–296. Search PubMed
  6. Short-contact tretinoin Veraldi S, Barbareschi M, Benardon S, Schianchi R. Short contact therapy of acne with tretinoin (pilot, open, multicenter study). J Dermatolog Treat 2013;24(5):374–376. doi:10.3109/09546634.2012.751085.
  7. Retinoids in pregnancy Tretinoin prescribing information (US and Canada). Kaplan YC, Ozsarfati J, Etwel F, Nickel C, Nulman I, Koren G. Pregnancy outcomes following first-trimester exposure to topical retinoids: a systematic review and meta-analysis. Br J Dermatol 2015;173(5):1132–1141. Systematic review and meta-analysis of first-trimester topical retinoid exposure (eight studies, 3,632,118 pregnancies). Front Drug Saf Regul 2026. doi:10.3389/fdsfr.2026.1864872.
Ch. 6Moisturizer and Cleanser: Simple and Cheap7
  1. Moisturizers for eczema van Zuuren et al. 2017 (see Chapter 1).
  2. Types of moisturizer in children Ridd MJ, Wells S, MacNeill SJ, et al. Effectiveness and safety of lotion, cream, gel, and ointment emollients for childhood eczema: a pragmatic, randomised, phase 4, superiority trial. Lancet Child Adolesc Health 2022;6(8):522–532. doi:10.1016/S2352-4642(22)00146-800146-8).
  3. Moisturizer prices Xu S, Kwa M, Lohman ME, Evers-Meltzer R, Silverberg JI. Consumer preferences, product characteristics, and potentially allergenic ingredients in best-selling moisturizers. JAMA Dermatol 2017;153(11):1099–1105. PMC5710429.
  4. Ceramide moisturizers Nugroho WT, Sawitri S, Astindari A, et al. The efficacy of moisturisers containing ceramide compared with other moisturisers in the management of atopic dermatitis: a systematic literature review and meta-analysis. Indian J Dermatol 2023;68(1):53–58. doi:10.4103/ijd.ijd_991_22. PMID 37151263. Chamlin SL, Kao J, Frieden IJ, et al. Ceramide-dominant barrier repair lipids alleviate childhood atopic dermatitis. J Am Acad Dermatol 2002.
  5. Moisturizers for healthy newborns Chalmers JR, Haines RH, Bradshaw LE, et al. Daily emollient during infancy for prevention of eczema: the BEEP randomised controlled trial. Lancet 2020;395(10228):962–972. Skjerven HO, Rehbinder EM, Vettukattil R, et al. Skin emollient and early complementary feeding to prevent infant atopic dermatitis (PreventADALL). Lancet 2020;395(10228):951–961. Kelleher MM, Phillips R, Brown SJ, et al. Skin care interventions in infants for preventing eczema and food allergy. Cochrane Database Syst Rev 2022. Search PubMed
  6. Soap and syndet cleansers Skin biophysical assessments of four types of soaps by forearm in-use test. J Cosmet Dermatol 2022;21(7):3127–3132. doi:10.1111/jocd.14589. PMID 34741581. Frosch PJ, Kligman AM. The soap chamber test: a new method for assessing the irritancy of soaps. J Am Acad Dermatol 1979;1(1):35–41.
  7. Petrolatum Ghadially R, Halkier-Sørensen L, Elias PM. Effects of petrolatum on stratum corneum structure and function. J Am Acad Dermatol 1992;26(3 Pt 2):387–396. Search PubMed
Ch. 7The Serum Shelf10
  1. Vitamin C Correia G, Magina S. Efficacy of topical vitamin C in melasma and photoaging: a systematic review. J Cosmet Dermatol 2023;22(7):1938–1945. Search PubMed
  2. Niacinamide Bissett DL, Miyamoto K, Sun P, Li J, Berge CA. Topical niacinamide reduces yellowing, wrinkling, red blotchiness, and hyperpigmented spots in aging facial skin. Int J Cosmet Sci 2004;26(5):231–238. Hakozaki T, Minwalla L, Zhuang J, et al. The effect of niacinamide on reducing cutaneous pigmentation and suppression of melanosome transfer. Br J Dermatol 2002;147(1):20–31. Search PubMed
  3. Glycolic acid and photoaging Thibault PK, Wlodarczyk J, Wenck A. A double-blind randomized clinical trial on the effectiveness of a daily glycolic acid 5% formulation in the treatment of photoaging. Dermatol Surg 1998;24(5):573–577. PMID 9598014.
  4. AHAs and sun sensitivity Kaidbey K, Sutherland B, Bennett P, et al. Topical glycolic acid enhances photodamage by ultraviolet light. Photodermatol Photoimmunol Photomed 2003. PMID 12713551. Comparison of glycolic and salicylic acid, 2009. PMID 19411163.
  5. Salicylic and azelaic acid for acne Reynolds RV, Yeung H, Cheng CE, et al. Guidelines of care for the management of acne vulgaris. J Am Acad Dermatol 2024;90(5):1006.e1–1006.e30. Search PubMed
  6. Azelaic acid and melasma Balina LM, Graupe K. The treatment of melasma: 20% azelaic acid versus 4% hydroquinone cream. Int J Dermatol 1991;30(12):893–895. PMID 1816137.
  7. Hyaluronic acid Pavicic T, Gauglitz GG, Lersch P, et al. Efficacy of cream-based novel formulations of hyaluronic acid of different molecular weights in anti-wrinkle treatment. J Drugs Dermatol 2011;10(9):990–1000. Search PubMed
  8. Peptides Robinson LR, Fitzgerald NC, Doughty DG, et al. Topical palmitoyl pentapeptide provides improvement in photoaged human facial skin. Int J Cosmet Sci 2005;27(3):155–160. Search PubMed
  9. Plant stem cells Trehan S, Michniak-Kohn B, Beri K. Plant stem cells in cosmetics: current trends and future directions. Future Sci OA 2017;3(4):FSO226. doi:10.4155/fsoa-2017-0026. PMC5674215.
  10. Snail secretion Tribó-Boixareu MJ, Parrado-Romero C, Rais B, et al. Clinical and histological efficacy of a secretion of the mollusk Cryptomphalus aspersa in the treatment of cutaneous photoaging. J Drugs Dermatol 2013. PMID 23652894. Randomized trial of snail secretion with snail egg extract, 2020. PMID 32308795.
Ch. 8Beauty You Swallow8
  1. Collagen supplements Myung SK, Park Y. Effects of collagen supplements on skin aging: a systematic review and meta-analysis of randomized controlled trials. Am J Med 2025;138(9):1264–1277. doi:10.1016/j.amjmed.2025.04.034. Pu SY, Huang YL, Pu CM, et al. Effects of oral collagen for skin anti-aging: a systematic review and meta-analysis. Nutrients 2023;15(9):2080. PMID 37432180.
  2. Nicotinamide and skin cancer Chen AC, Martin AJ, Choy B, et al. A phase 3 randomized trial of nicotinamide for skin-cancer chemoprevention. N Engl J Med 2015;373(17):1618–1626. PMID 26488693.
  3. Biotin and lab tests US Food and Drug Administration. The FDA warns that biotin may interfere with lab tests: FDA safety communication, November 28, 2017 (updated 2019).
  4. Biotin and skin Patel DP, Swink SM, Castelo-Soccio L. A review of the use of biotin for hair loss. Skin Appendage Disord 2017;3(3):166–169. PMID 28879195.
  5. Sunscreen pills US Food and Drug Administration warning letters to sellers of oral "sunscreen" supplements, May 2018, and statement by the FDA Commissioner.
  6. Water intake Akdeniz M, Tomova-Simitchieva T, Dobos G, Blume-Peytavi U, Kottner J. Does dietary fluid intake affect skin hydration in healthy humans? A systematic literature review. Skin Res Technol 2018;24(3):459–465. PMID 29392767.
  7. Low-glycemic diet and acne Smith RN, Mann NJ, Braue A, Mäkeläinen H, Varigos GA. A low-glycemic-load diet improves symptoms in acne vulgaris patients: a randomized controlled trial. Am J Clin Nutr 2007;86(1):107–115. PMID 17616769.
  8. Milk and acne Juhl CR, Bergholdt HKM, Miller IM, et al. Dairy intake and acne vulgaris: a systematic review and meta-analysis of 78,529 children, adolescents, and young adults. Nutrients 2018;10(8):1049. PMID 30096883.
Ch. 9Devices at Home, Treatments in the Clinic7
  1. LED light therapy Jagdeo J, Austin E, Mamalis A, et al. Light-emitting diodes in dermatology: a systematic review of randomized controlled trials. Lasers Surg Med 2018;50(6):613–628. PMID 29356026. Cohen M, Austin E, Masub N, Kurtti A, George C, Jagdeo J. Home-based devices in dermatology: a systematic review of safety and efficacy. Arch Dermatol Res 2022;314(3):239–246. doi:10.1007/s00403-021-02231-0.
  2. Light mask recall Johnson & Johnson voluntary recall of the Neutrogena Light Therapy Acne Mask, July 2019; Therapeutic Goods Administration (Australia) advice.
  3. Botulinum toxin Glogau R, Kane M, Beddingfield F, et al. OnabotulinumtoxinA: a meta-analysis of duration of effect in the treatment of glabellar lines. Dermatol Surg 2012;38(11):1794–1803. PMID 23106853.
  4. Filler complications Beleznay K, Carruthers JDA, Humphrey S, Jones D. Reviews of vision loss after filler injection, Aesthet Surg J 2015 and 2019, update 2024;44(10):1091. Kapoor KM, et al. Vision loss associated with hyaluronic acid fillers: a systematic review of literature. Aesthetic Plast Surg 2020. PMID 31822960.
  5. Microneedling for acne scars Sitohang IBS, Sirait SAP, Suryanegara J. Microneedling in the treatment of atrophic scars: a systematic review of randomised controlled trials. Int Wound J 2021;18(5):577–585. doi:10.1111/iwj.13559. PMID 33538106.
  6. Laser resurfacing for photoaging No reliable systematic review found; labeled Debated.
  7. Lasers and dark marks in skin of color Bin Dakhil A, Shadid A, Altalhab S. Postinflammatory hyperpigmentation after carbon dioxide laser: review of prevention and risk factors. Dermatol Reports 2023;15:9703. doi:10.4081/dr.2023.9703. Sowash M, Alster T. Review of laser treatments for post-inflammatory hyperpigmentation in skin of color. Am J Clin Dermatol 2023;24(3):381–396. doi:10.1007/s40257-023-00759-7.
Ch. 10Acne After Twenty8
  1. Adult acne prevalence Collier CN, Harper JC, Cafardi JA, et al. The prevalence of acne in adults 20 years and older. J Am Acad Dermatol 2008;58(1):56–59. Search PubMed
  2. Acne treatment guideline Reynolds et al. 2024 (see Chapter 7).
  3. Benzoyl peroxide strengths Mills OH Jr, Kligman AM, Pochi P, Comite H. Comparing 2.5%, 5%, and 10% benzoyl peroxide on inflammatory acne vulgaris. Int J Dermatol 1986;25(10):664–667. Search PubMed
  4. Antibiotic resistance Zaenglein AL, Pathy AL, Schlosser BJ, et al. Guidelines of care for the management of acne vulgaris. J Am Acad Dermatol 2016;74(5):945–973, doi:10.1016/j.jaad.2015.12.037; Reynolds et al. 2024 (see Chapter 7).
  5. Over-the-counter adapalene US Food and Drug Administration press announcement, July 8, 2016.
  6. Birth control pills Arowojolu AO, Gallo MF, Lopez LM, Grimes DA. Combined oral contraceptive pills for treatment of acne. Cochrane Database Syst Rev 2012;(7):CD004425. Search PubMed
  7. Spironolactone Santer M, Lawrence M, Renz S, et al. Effectiveness of spironolactone for women with acne vulgaris (SAFA) in England and Wales: pragmatic, multicentre, phase 3, double blind, randomised controlled trial. BMJ 2023;381:e074349. Search PubMed
  8. Isotretinoin and mood Tan NKW, Tang A, MacAlevey NCYL, Tan BKJ, Oon HH. Risk of suicide and psychiatric disorders among isotretinoin users: a meta-analysis. JAMA Dermatol 2023 (published 2024;160(1):54–62). PMC10687715.
Ch. 11Dark Spots and Melasma9
  1. Melasma relapse Cohort study of 104 patients treated with Q-switched Nd:YAG laser for melasma, Northern Jiangsu Provincial People's Hospital, China. Int J Clin Exp Med 19(1).
  2. Tinted sunscreen Castanedo-Cázares et al. 2014 (see Chapter 4).
  3. Hydroquinone and triple-combination cream Rajaratnam R, Halpern J, Salim A, Emmett C. Interventions for melasma. Cochrane Database Syst Rev 2010;(7):CD003583. Search PubMed
  4. Hydroquinone rules and ochronosis US Food and Drug Administration, over-the-counter monograph reform under the CARES Act (September 2020); FDA safety information on skin-lightening products.
  5. Azelaic acid Balina and Graupe 1991 (see Chapter 7).
  6. Tranexamic acid Kim HJ, Moon SH, Cho SH, Lee JD, Kim HS. Efficacy and safety of tranexamic acid in melasma: a meta-analysis and systematic review. Acta Derm Venereol 2017;97(7):776–781. Meta-analysis of four randomized trials (480 patients) of oral tranexamic acid with triple-combination cream, 2024. Tranexamic acid prescribing information (clot risk). Search PubMed
  7. Lasers for melasma Lai D, Zhou S, Cheng S, Liu H, Cui Y. Laser therapy in the treatment of melasma: a systematic review and meta-analysis. Lasers Med Sci 2022;37(4):2099–2110. doi:10.1007/s10103-022-03514-2. Efficacy and safety of picosecond laser for the treatment of melasma: a systematic review and meta-analysis. Lasers Med Sci 2023;38(1):84. doi:10.1007/s10103-023-03744-y. Review of lasers in melasma. PMC5418955.
  8. Mercury in whitening creams World Health Organization. Elimination of mercury-containing skin lightening products; WHO news release, February 14, 2023. Minamata Convention on Mercury, Article 4. Zero Mercury Working Group product testing report, 2018–2019.
  9. Corticosteroids in whitening creams Skin-lightening cosmetics: frequent, potentially severe adverse effects. Prescrire Int 2011;20(119):208–215.
Ch. 12Sensitive, Red, Itchy Skin7
  1. Definition of sensitive skin Misery L, Ständer S, Szepietowski JC, et al. Definition of sensitive skin: an expert position paper from the Special Interest Group on Sensitive Skin of the International Forum for the Study of Itch. Acta Derm Venereol 2017;97(1):4–6. Search PubMed
  2. Irritant and allergic reactions to cosmetics DermNet NZ, Contact reactions to cosmetics. Prospective study of 151 patients with suspected cosmetic dermatitis, Sweden.
  3. Patch testing Johansen JD, Aalto-Korte K, Agner T, et al. European Society of Contact Dermatitis guideline for diagnostic patch testing. Contact Dermatitis 2015;73(4):195–221. Search PubMed
  4. Repeated open application test DermNet NZ, Open application test.
  5. Rosacea treatments van Zuuren EJ, Fedorowicz Z, Carter B, van der Linden MMD, Charland L. Interventions for rosacea. Cochrane Database Syst Rev 2015;(4):CD003262, doi:10.1002/14651858.CD003262.pub5, PMID 25919144.
  6. Topical steroid withdrawal Hajar T, Leshem YA, Hanifin JM, et al. A systematic review of topical corticosteroid withdrawal ("steroid addiction") in patients with atopic dermatitis and other dermatoses. J Am Acad Dermatol 2015;72(3):541–549. National Eczema Society, British Dermatological Nursing Group and British Association of Dermatologists, joint statement on topical steroid withdrawal, February 2024. Search PubMed
  7. Perioral dermatitis StatPearls, Perioral dermatitis (NCBI Bookshelf NBK525968).
Ch. 13Wrinkles and Aging: What's Realistic?6
  1. Facial skeleton and aging Mendelson B, Wong CH. Changes in the facial skeleton with aging: implications and clinical applications in facial rejuvenation. Aesthetic Plast Surg 2012;36(4):753–760. PMC3404279.
  2. Quitting smoking Serri R, Romano MC, Sparavigna A. "Quitting smoking rejuvenates the skin": results of a pilot project on smoking cessation conducted in Milan, Italy. Skinmed 2010;8(1):23–29. PMID 20839421.
  3. Sleep loss and appearance Axelsson J, Sundelin T, Ingre M, et al. Beauty sleep: experimental study on the perceived health and attractiveness of sleep deprived people. BMJ 2010;341:c6614. PMC3001961. Sundelin T, Lekander M, Kecklund G, et al. Cues of fatigue: effects of sleep deprivation on facial appearance. Sleep 2013;36(9):1355–1360. PMC3738045.
  4. Sugar and glycation Danby FW. Nutrition and aging skin: sugar and glycation. Clin Dermatol 2010;28(4):409–411, doi:10.1016/j.clindermatol.2010.03.018, PMID 20620757.
  5. Vegetables and wrinkles Nagata C, Nakamura K, Wada K, et al. Association of dietary fat, vegetables and antioxidant micronutrients with skin ageing in Japanese women. Br J Nutr 2010;103(10):1493–1498. Search PubMed
  6. Hormone therapy and wrinkles Owen CM, Pal L, Mumford SL, et al. Effects of hormones on skin wrinkles and rigidity vary by race/ethnicity: four-year follow-up from the ancillary skin study of the Kronos Early Estrogen Prevention Study. Fertil Steril 2016;106(5):1170–1175. The 2022 hormone therapy position statement of The North American Menopause Society. Menopause 2022. PMID 35797481.
Ch. 14Your Routine and Your Budget3
  1. A short routine Summary of Chapters 1, 4, 5 and 6: Hughes et al. 2013; Sitohang et al. 2022; van Zuuren et al. 2017.
  2. Children's skin care on social media Hales M, Lagu T, Rigali S, Paller A, Liszewski W. Pediatric skin care regimens on TikTok. Pediatrics 2025 (published online June 9, 2025). doi:10.1542/peds.2024-070309.
  3. Skin care for tweens and teens American Academy of Pediatrics, HealthyChildren.org. Trendy skin care for tweens and teens: is it safe? American Academy of Dermatology, A dermatologist's guide to skincare.
BackWorksheets at the back of the book1
  1. ABCDE signs of melanoma American Academy of Dermatology public guidance.
Cover of Is It Sadness or Depression?

Vol. 11

Is It Sadness or Depression?

Evidence last reviewed October 12, 2026

Ch. 1Is It Sadness or Depression?8
  1. Effective treatments exist National Institute for Health and Care Excellence (NICE). Depression in adults: treatment and management. NICE guideline NG222, June 2022. World Health Organization. Depressive disorder (depression). Fact sheet, August 29, 2025. Open Open
  2. How long depressive episodes last Spijker J, de Graaf R, Bijl RV, Beekman ATF, Ormel J, Nolen WA. Duration of major depressive episodes in the general population: results from the Netherlands Mental Health Survey and Incidence Study (NEMESIS). Br J Psychiatry 2002;181(3):208–213. doi:10.1192/bjp.181.3.208.
  3. Diagnostic criteria American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR). 2022. World Health Organization. International Classification of Diseases, 11th Revision (ICD-11), 6A70–6A71.
  4. Telling grief from depression Iglewicz A, Seay K, Zetumer SD, Zisook S. The removal of the bereavement exclusion in the DSM-5: exploring the evidence. Curr Psychiatry Rep 2013;15(11):413. PMID 24136623. Kavan MG, Barone EJ. Grief and major depression: controversy over changes in DSM-5 diagnostic criteria. Am Fam Physician 2014;90(10):690–694.
  5. Accuracy of the PHQ-2 Levis B, Sun Y, He C, et al. Accuracy of the PHQ-2 alone and in combination with the PHQ-9 for screening to detect major depression: systematic review and meta-analysis. JAMA 2020;323(22):2290–2300. PMID 32515813.
  6. PHQ-9 scores overestimate prevalence Levis B, Benedetti A, Ioannidis JPA, et al. Patient Health Questionnaire-9 scores do not accurately estimate depression prevalence: individual participant data meta-analysis. J Clin Epidemiol 2020;122:115–128.e1. doi:10.1016/j.jclinepi.2020.02.002.
  7. Accuracy of the PHQ-9 and online quizzes Levis B, Benedetti A, Thombs BD. Accuracy of Patient Health Questionnaire-9 (PHQ-9) for screening to detect major depression: individual participant data meta-analysis. BMJ 2019;365:l1476. PMID 30967483.
  8. The PHQ-9 and PHQ-2 Kroenke K, Spitzer RL, Williams JBW. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med 2001;16(9):606–613. PMC1495268. Kroenke K, Spitzer RL, Williams JBW. The Patient Health Questionnaire-2: validity of a two-item depression screener. Med Care 2003;41(11):1284–1292.
Ch. 2What Is Sadness For?8
  1. Mild sad mood and thinking Forgas JP. Don't worry, be sad! On the cognitive, motivational, and interpersonal benefits of negative mood. Curr Dir Psychol Sci 2013;22(3):225–232. doi:10.1177/0963721412474458.
  2. Tears and helping Zickfeld JH, van de Ven N, Pich O, et al. Tears evoke the intention to offer social support: a systematic investigation of the interpersonal effects of emotional crying across 41 countries. J Exp Soc Psychol 2021;95:104137. doi:10.1016/j.jesp.2021.104137.
  3. Accepting negative emotions Ford BQ, Lam P, John OP, Mauss IB. The psychological health benefits of accepting negative emotions and thoughts: laboratory, diary, and longitudinal evidence. J Pers Soc Psychol 2018;115(6):1075–1092. doi:10.1037/pspp0000157. PMC5767148.
  4. Suppressing emotions Gross JJ, John OP. Individual differences in two emotion regulation processes: implications for affect, relationships, and well-being. J Pers Soc Psychol 2003;85(2):348–362. PMID 12916575.
  5. Putting feelings into words Lieberman MD, Eisenberger NI, Crockett MJ, et al. Putting feelings into words: affect labeling disrupts amygdala activity in response to affective stimuli. Psychol Sci 2007;18(5):421–428. Torre JB, Lieberman MD. Putting feelings into words: affect labeling as implicit emotion regulation. Emotion Review 2018;10(2):116–124. Search PubMed
  6. Expressive writing Frattaroli J. Experimental disclosure and its moderators: a meta-analysis. Psychol Bull 2006;132(6):823–865. PMID 17073523. Guo L. The delayed, durable effect of expressive writing on depression, anxiety and stress: a meta-analytic review of studies with long-term follow-ups. Br J Clin Psychol 2023;62(1):272–297. doi:10.1111/bjc.12408.
  7. Medicalizing sadness Horwitz AV, Wakefield JC. The Loss of Sadness: How Psychiatry Transformed Normal Sorrow into Depressive Disorder. Oxford University Press; 2007.
  8. Missed and over-diagnosed depression in primary care Mitchell AJ, Vaze A, Rao S. Clinical diagnosis of depression in primary care: a meta-analysis. Lancet 2009;374(9690):609–619. PMID 19640579.
Ch. 3What Depression Really Is6
  1. How many people have depression World Health Organization. Depressive disorder (depression). Fact sheet, August 29, 2025. GBD 2019 Mental Disorders Collaborators. Global, regional, and national burden of 12 mental disorders in 204 countries and territories, 1990–2019. Lancet Psychiatry 2022;9(2):137–150. PMID 35026139. Open
  2. How few receive adequate treatment Thornicroft G, Chatterji S, Evans-Lacko S, et al. Undertreatment of people with major depressive disorder in 21 countries. Br J Psychiatry 2017;210(2):119–124. Search PubMed
  3. No biological test for depression DSM-5-TR (Chapter 1). NICE NG222 (Chapter 1). Ang SH, et al. The clinical utility of biomarkers in diagnosing major depressive disorder in adults: a systematic review of literature from 2013 to 2023. Eur Psychiatry 2025. doi:10.1192/j.eurpsy.2025.793. PMC12438469. The review found many candidate markers but none in routine diagnostic use. Open
  4. Severity and first-line treatment NICE NG222 (Chapter 1), including its visual summaries of first-line treatments for less severe and more severe depression. Open
  5. Recurrence Hardeveld F, Spijker J, de Graaf R, Nolen WA, Beekman ATF. Prevalence and predictors of recurrence of major depressive disorder in the adult population. Acta Psychiatr Scand 2010;122(3):184–191. Search PubMed
  6. Persistent depression and psychotic depression DSM-5-TR (Chapter 1). ICD-11, 6A72 and 6A70.
Ch. 4Grief, Burnout, or Something Else?10
  1. Grief and depression Iglewicz et al. 2013 (Chapter 1).
  2. Prolonged grief disorder: definitions Eisma MC. Prolonged grief disorder in ICD-11 and DSM-5-TR: challenges and controversies. Aust N Z J Psychiatry 2023;57(7):944–951. doi:10.1177/00048674231154206. PMC10291380.
  3. How common prolonged grief is Lundorff M, Holmgren H, Zachariae R, Farver-Vestergaard I, O'Connor M. Prevalence of prolonged grief disorder in adult bereavement: a systematic review and meta-analysis. J Affect Disord 2017;212:138–149. PMID 28167398.
  4. Treating prolonged grief Shear MK, Reynolds CF 3rd, Simon NM, et al. Optimizing treatment of complicated grief: a randomized clinical trial. JAMA Psychiatry 2016;73(7):685–694. doi:10.1001/jamapsychiatry.2016.0892.
  5. Burnout World Health Organization. Burn-out an "occupational phenomenon": International Classification of Diseases. Statement, May 2019; ICD-11 QD85. Bianchi R, Verkuilen J, Schonfeld IS, et al. Is burnout a depressive condition? A 14-sample meta-analytic and bifactor analytic study. Clin Psychol Sci 2021;9(4):579–597. doi:10.1177/2167702620979597. Koutsimani P, Montgomery A, Georganta K. The relationship between burnout, depression, and anxiety: a systematic review and meta-analysis. Front Psychol 2019.
  6. Adjustment disorder ICD-11, 6B43.
  7. Anxiety alongside depression Lamers F, van Oppen P, Comijs HC, et al. Comorbidity patterns of anxiety and depressive disorders in a large cohort study: the Netherlands Study of Depression and Anxiety (NESDA). J Clin Psychiatry 2011;72(3):341–348. Search PubMed
  8. Bipolar disorder mistaken for depression Hirschfeld RMA, Lewis L, Vornik LA. Perceptions and impact of bipolar disorder: how far have we really come? J Clin Psychiatry 2003;64(2):161–174.
  9. Antidepressants alone in bipolar disorder Viktorin A, Lichtenstein P, Thase ME, et al. The risk of switch to mania in patients with bipolar disorder during treatment with an antidepressant alone and in combination with a mood stabilizer. Am J Psychiatry 2014;171(10):1067–1073. Yatham LN, Kennedy SH, Parikh SV, et al. Canadian Network for Mood and Anxiety Treatments (CANMAT) and International Society for Bipolar Disorders (ISBD) 2018 guidelines for the management of patients with bipolar disorder. Bipolar Disord 2018;20(2):97–170. doi:10.1111/bdi.12609.
  10. Languishing Keyes CLM. The mental health continuum: from languishing to flourishing in life. J Health Soc Behav 2002;43(2):207–222. Search PubMed
Ch. 5When the Body Is Behind the Mood10
  1. Hypothyroidism and depressive symptoms Bode H, Ivens B, Bschor T, et al. Association of hypothyroidism and clinical depression: a systematic review and meta-analysis. JAMA Psychiatry 2021;78(12):1375–1383. doi:10.1001/jamapsychiatry.2021.2506. PMID 34524390. Hage MP, Azar ST. The link between thyroid function and depression. J Thyroid Res 2012;2012:590648. PMID 22220285.
  2. Subclinical hypothyroidism Tang R, Wang J, Yang L, et al. Subclinical hypothyroidism and depression: a systematic review and meta-analysis. Front Endocrinol 2019;10:340. PMC6558168.
  3. Depression after stroke Hackett ML, Pickles K. Part I: frequency of depression after stroke: an updated systematic review and meta-analysis of observational studies. Int J Stroke 2014;9(8):1017–1025. PMID 25117911.
  4. Alcohol and depression Fergusson DM, Boden JM, Horwood LJ. Tests of causal links between alcohol abuse or dependence and major depression. Arch Gen Psychiatry 2009;66(3):260–266. doi:10.1001/archgenpsychiatry.2008.543. Boden JM, Fergusson DM. Alcohol and depression. Addiction 2011;106(5):906–914.
  5. Corticosteroids Koning ACAM, van der Meulen M, Schaap D, et al. Neuropsychiatric adverse effects of synthetic glucocorticoids: a systematic review and meta-analysis. J Clin Endocrinol Metab 2024;109(6). doi:10.1210/clinem/dgad701. PMC11099480.
  6. Interferon alpha Udina M, Castellví P, Moreno-España J, et al. Interferon-induced depression in chronic hepatitis C: a systematic review and meta-analysis. J Clin Psychiatry 2012;73(8):1128–1138. Search PubMed
  7. Isotretinoin Huang YC, Cheng YC. Isotretinoin treatment for acne and risk of depression: a systematic review and meta-analysis. J Am Acad Dermatol 2017;76(6):1068–1076.e9. PMID 28291553. Li C, Chen J, Wang W, et al. Use of isotretinoin and risk of depression in patients with acne: a systematic review and meta-analysis. BMJ Open 2019;9(1):e021549.
  8. Hormonal contraception Skovlund CW, Mørch LS, Kessing LV, Lidegaard Ø. Association of hormonal contraception with depression. JAMA Psychiatry 2016;73(11):1154–1162.
  9. Blood pressure medicines Kessing LV, Rytgaard HC, Ekstrøm CT, et al. Antihypertensive drugs and risk of depression: a nationwide population-based study. Hypertension 2020;76(4). doi:10.1161/HYPERTENSIONAHA.120.15605.
  10. Vitamin D Okereke OI, Reynolds CF 3rd, Mischoulon D, et al. Effect of long-term vitamin D3 supplementation vs placebo on risk of depression or clinically relevant depressive symptoms and on change in mood scores: a randomized clinical trial. JAMA 2020;324(5):471–480. doi:10.1001/jama.2020.10224.
Ch. 6What Happens in the Brain and Body6
  1. The serotonin theory Moncrieff J, Cooper RE, Stockmann T, Amendola S, Hengartner MP, Horowitz MA. The serotonin theory of depression: a systematic umbrella review of the evidence. Mol Psychiatry 2023;28(8):3243–3256. doi:10.1038/s41380-022-01661-0. PMID 35854107. Jauhar S, Cowen PJ, Browning M, et al. A leaky umbrella has little value: evidence clearly indicates the serotonin system is implicated in depression. Mol Psychiatry 2023;28(8):3149–3152. doi:10.1038/s41380-023-02095-y.
  2. Genes Sullivan PF, Neale MC, Kendler KS. Genetic epidemiology of major depression: review and meta-analysis. Am J Psychiatry 2000;157(10):1552–1562. PMID 11007705. Howard DM, Adams MJ, Clarke TK, et al. Genome-wide meta-analysis of depression identifies 102 independent variants and highlights the importance of the prefrontal brain regions. Nat Neurosci 2019;22(3):343–352. PMID 30718901.
  3. Low-grade inflammation Osimo EF, Baxter LJ, Lewis G, Jones PB, Khandaker GM. Prevalence of low-grade inflammation in depression: a systematic review and meta-analysis of CRP levels. Psychol Med 2019;49(12):1958–1970. PMC6712955.
  4. Anti-inflammatory treatment Köhler-Forsberg O, Lydholm CN, Hjorthøj C, et al. Efficacy of anti-inflammatory treatment on major depressive disorder or depressive symptoms: meta-analysis of clinical trials. Acta Psychiatr Scand 2019;139(5):404–419. doi:10.1111/acps.13016.
  5. Bleeding risk with SSRIs and anti-inflammatory painkillers Anglin R, Yuan Y, Moayyedi P, et al. Risk of upper gastrointestinal bleeding with selective serotonin reuptake inhibitors with or without concurrent nonsteroidal anti-inflammatory use: a systematic review and meta-analysis. Am J Gastroenterol 2014;109(6):811–819. PMID 24777151.
  6. Insomnia and depression Baglioni C, Battagliese G, Feige B, et al. Insomnia as a predictor of depression: a meta-analytic evaluation of longitudinal epidemiological studies. J Affect Disord 2011;135(1–3):10–19. Search PubMed
Ch. 7Life, Stress, and Loneliness6
  1. Life events Kendler KS, Hettema JM, Butera F, Gardner CO, Prescott CA. Life event dimensions of loss, humiliation, entrapment, and danger in the prediction of onsets of major depression and generalized anxiety. Arch Gen Psychiatry 2003;60(8):789–796. PMID 12912762.
  2. Adverse childhood experiences Hughes K, Bellis MA, Hardcastle KA, et al. The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysis. Lancet Public Health 2017;2(8):e356–e366. Search PubMed
  3. Having someone to confide in Choi KW, Stein MB, Nishimi KM, et al. An exposure-wide and Mendelian randomization approach to identifying modifiable factors for the prevention of depression. Am J Psychiatry 2020;177(10):944–954. Search PubMed
  4. Debt Richardson T, Elliott P, Roberts R. The relationship between personal unsecured debt and mental and physical health: a systematic review and meta-analysis. Clin Psychol Rev 2013;33(8):1148–1162. PMID 24121465.
  5. Social media Orben A, Przybylski AK. The association between adolescent well-being and digital technology use. Nat Hum Behav 2019;3:173–182. doi:10.1038/s41562-018-0506-1. Haidt J. The Anxious Generation: How the Great Rewiring of Childhood Is Causing an Epidemic of Mental Illness. New York: Penguin Press; 2024.
  6. Rumination Nolen-Hoeksema S. The role of rumination in depressive disorders and mixed anxiety/depressive symptoms. J Abnorm Psychol 2000;109(3):504–511. Watkins ER, Mullan E, Wingrove J, et al. Rumination-focused cognitive-behavioural therapy for residual depression: phase II randomised controlled trial. Br J Psychiatry 2011;199(4):317–322. Search PubMed
Ch. 8Hormones and Mood: Periods, Pregnancy, Menopause10
  1. Depression in women and around childbirth World Health Organization, depression fact sheet (Chapter 3).
  2. How common PMDD is Reilly TJ, Patel S, Unachukwu IC, et al. The prevalence of premenstrual dysphoric disorder: systematic review and meta-analysis. J Affect Disord 2024;349:534–540. doi:10.1016/j.jad.2024.01.066. PMID 38199397.
  3. SSRIs for PMDD Jespersen C, Lauritsen MP, Frokjaer VG, Schroll JB. Selective serotonin reuptake inhibitors for premenstrual syndrome and premenstrual dysphoric disorder. Cochrane Database Syst Rev 2024;8:CD001396. PMID 39140320. The review found SSRIs effective whether taken only in the second half of the cycle or every day.
  4. Postpartum depression NICE. Antenatal and postnatal mental health: clinical management and service guidance. CG192, 2014 (updated 2020). American College of Obstetricians and Gynecologists. Screening and diagnosis of mental health conditions during pregnancy and postpartum. Clinical Practice Guideline No. 4. Obstet Gynecol 2023;141(6). Treatment and management of mental health conditions during pregnancy and postpartum. Clinical Practice Guideline No. 5. Obstet Gynecol 2023;141(6):1262–1288. US Food and Drug Administration. FDA approves first oral treatment for postpartum depression (zuranolone). Press release, August 2023. Open
  5. Preventing perinatal depression US Preventive Services Task Force. Interventions to prevent perinatal depression: US Preventive Services Task Force recommendation statement. JAMA 2019;321(6):580–587. doi:10.1001/jama.2019.0007.
  6. Fathers Paulson JF, Bazemore SD. Prenatal and postpartum depression in fathers and its association with maternal depression: a meta-analysis. JAMA 2010;303(19):1961–1969. doi:10.1001/jama.2010.605.
  7. Postpartum psychosis Harlow BL, Vitonis AF, Sparen P, et al. Incidence of hospitalization for postpartum psychotic and bipolar episodes in women with and without prior prepregnancy or prenatal psychiatric hospitalizations. Arch Gen Psychiatry 2007;64(1):42–48. PMID 17199053. Bergink V, Rasgon N, Wisner KL. Postpartum psychosis: madness, mania, and melancholia in motherhood. Am J Psychiatry 2016;173(12):1179–1188.
  8. Risks of untreated depression in pregnancy Grote NK, Bridge JA, Gavin AR, et al. A meta-analysis of depression during pregnancy and the risk of preterm birth, low birth weight, and intrauterine growth restriction. Arch Gen Psychiatry 2010;67(10):1012–1024. Search PubMed
  9. Perimenopause Maki PM, Kornstein SG, Joffe H, et al. Guidelines for the evaluation and treatment of perimenopausal depression: summary and recommendations. Menopause 2018;25(10):1069–1085. doi:10.1097/GME.0000000000001174. PMID 30179986.
  10. The Edinburgh scale Cox JL, Holden JM, Sagovsky R. Detection of postnatal depression: development of the 10-item Edinburgh Postnatal Depression Scale. Br J Psychiatry 1987;150:782–786. Search PubMed
Ch. 9Why Doesn't My Depression Look Like Depression?5
  1. Suicide rates in men and women World Health Organization. Suicide worldwide in 2019: global health estimates. 2021.
  2. Depression in men Martin LA, Neighbors HW, Griffith DM. The experience of symptoms of depression in men vs women: analysis of the National Comorbidity Survey Replication. JAMA Psychiatry 2013;70(10):1100–1106. PMID 23986338.
  3. Depression in young people DSM-5-TR (Chapter 1). NICE. Depression in children and young people: identification and management. NG134, 2019. Recommends a psychological therapy, such as individual cognitive behavioral therapy, as the first treatment for moderate to severe depression in young people aged 12 to 18. Open
  4. Depression in later life and dementia Diniz BS, Butters MA, Albert SM, Dew MA, Reynolds CF 3rd. Late-life depression and risk of vascular dementia and Alzheimer's disease: systematic review and meta-analysis of community-based cohort studies. Br J Psychiatry 2013;202(5):329–335.
  5. Culture and how depression is described Ryder AG, Yang J, Zhu X, et al. The cultural shaping of depression: somatic symptoms in China, psychological symptoms in North America? J Abnorm Psychol 2008;117(2):300–313. Kleinman A. Social Origins of Distress and Disease: Depression, Neurasthenia, and Pain in Modern China. Yale University Press; 1986.
Ch. 10Where to Start: The First Two Weeks4
  1. Behavioral activation Richards DA, Ekers D, McMillan D, et al. Cost and Outcome of Behavioural Activation versus Cognitive Behavioural Therapy for Depression (COBRA): a randomised, controlled, non-inferiority trial. Lancet 2016;388(10047):871–880. PMC5007415. Ekers D, Webster L, Van Straten A, Cuijpers P, Richards D, Gilbody S. Behavioural activation for depression; an update of meta-analysis of effectiveness and sub group analysis. PLoS One 2014;9(6):e100100. doi:10.1371/journal.pone.0100100.
  2. Guided self-help Cuijpers P, Donker T, van Straten A, Li J, Andersson G. Is guided self-help as effective as face-to-face psychotherapy for depression and anxiety disorders? A systematic review and meta-analysis of comparative outcome studies. Psychol Med 2010;40(12). doi:10.1017/S0033291710000772.
  3. Unguided online self-help Karyotaki E, Riper H, Twisk J, et al. Efficacy of self-guided internet-based cognitive behavioral therapy in the treatment of depressive symptoms: a meta-analysis of individual participant data. JAMA Psychiatry 2017;74(4):351–359. Search PubMed
  4. Behavioral activation techniques Martell CR, Dimidjian S, Herman-Dunn R. Behavioral Activation for Depression: A Clinician's Guide. Guilford Press; 2010.
Ch. 11Movement, Sleep, Food, Light, and Supplements7
  1. Exercise Noetel M, Sanders T, Gallardo-Gómez D, et al. Effect of exercise for depression: systematic review and network meta-analysis of randomised controlled trials. BMJ 2024;384:e075847 (correction May 2024). Search PubMed
  2. Treating insomnia to prevent depression Irwin MR, Carrillo C, Sadeghi N, et al. Prevention of incident and recurrent major depression in older adults with insomnia: a randomized clinical trial. JAMA Psychiatry 2022;79(1):33–41. Search PubMed
  3. Diet Jacka FN, O'Neil A, Opie R, et al. A randomised controlled trial of dietary improvement for adults with major depression (the "SMILES" trial). BMC Med 2017;15:23. Search PubMed
  4. Light therapy Golden RN, Gaynes BN, Ekstrom RD, et al. The efficacy of light therapy in the treatment of mood disorders: a review and meta-analysis of the evidence. Am J Psychiatry 2005;162(4):656–662. Search PubMed
  5. St John's wort Linde K, Berner MM, Kriston L. St John's wort for major depression. Cochrane Database Syst Rev 2008;(4):CD000448. National Center for Complementary and Integrative Health. St. John's wort and depression: in depth. Fact sheet. National Institute of Diabetes and Digestive and Kidney Diseases. St. John's wort. In: LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. NCBI Bookshelf NBK548880. Open Open
  6. Omega-3 Appleton KM, Voyias PD, Sallis HM, et al. Omega-3 fatty acids for depression in adults. Cochrane Database Syst Rev 2021;11:CD004692. PMID 34817851.
  7. Saffron Marx W, Lane M, Rocks T, et al. Effect of saffron supplementation on symptoms of depression and anxiety: a systematic review and meta-analysis. Nutr Rev 2019;77(8):557–571. PMID 31135916.
Ch. 12Talking Therapies: What Works and How to Find One6
  1. Structured therapies compared Cuijpers P, van Straten A, Andersson G, van Oppen P. Psychotherapy for depression in adults: a meta-analysis of comparative outcome studies. J Consult Clin Psychol 2008;76(6):909–922. Search PubMed
  2. Publication bias Cuijpers P, Smit F, Bohlmeijer E, Hollon SD, Andersson G. Efficacy of cognitive-behavioural therapy and other psychological treatments for adult depression: meta-analytic study of publication bias. Br J Psychiatry 2010;196(3):173–178. PMID 20194536.
  3. Combining therapy and medication Cuijpers P, Sijbrandij M, Koole SL, Andersson G, Beekman AT, Reynolds CF 3rd. Adding psychotherapy to antidepressant medication in depression and anxiety disorders: a meta-analysis. World Psychiatry 2014;13(1):56–67. PMID 24497254.
  4. The Friendship Bench Chibanda D, Weiss HA, Verhey R, et al. Effect of a primary care–based psychological intervention on symptoms of common mental disorders in Zimbabwe: a randomized clinical trial. JAMA 2016;316(24). doi:10.1001/jama.2016.19102.
  5. Phone apps Linardon J, Cuijpers P, Carlbring P, Messer M, Fuller-Tyszkiewicz M. The efficacy of app-supported smartphone interventions for mental health problems: a meta-analysis of randomized controlled trials. World Psychiatry 2019;18(3):325–336. Search PubMed
  6. The therapeutic alliance Flückiger C, Del Re AC, Wampold BE, Horvath AO. The alliance in adult psychotherapy: a meta-analytic synthesis. Psychotherapy 2018;55(4):316–340. PMID 29792475.
Ch. 13Antidepressants and Other Medical Treatments13
  1. Antidepressants compared with placebo Cipriani A, Furukawa TA, Salanti G, et al. Comparative efficacy and acceptability of 21 antidepressant drugs for the acute treatment of adults with major depressive disorder: a systematic review and network meta-analysis. Lancet 2018;391(10128):1357–1366. Search PubMed
  2. Average effect and substantial responders Stone MB, Yaseen ZS, Miller BJ, Richardville K, Kalaria SN, Kirsch I. Response to acute monotherapy for major depressive disorder in randomized, placebo controlled trials submitted to the US Food and Drug Administration: individual participant data analysis. BMJ 2022;378:e067606. PMID 35918097.
  3. Severity and antidepressant effect Fournier JC, DeRubeis RJ, Hollon SD, et al. Antidepressant drug effects and depression severity: a patient-level meta-analysis. JAMA 2010;303(1):47–53. Furukawa TA, Maruo K, Noma H, et al. Initial severity of major depression and efficacy of new generation antidepressants: individual participant data meta-analysis. Acta Psychiatr Scand 2018. Search PubMed
  4. The under-25 warning US Food and Drug Administration. FDA proposes new warnings about suicidal thinking, behavior in young adults who take antidepressant medications. News release, May 2, 2007.
  5. Continuing treatment Geddes JR, Carney SM, Davies C, et al. Relapse prevention with antidepressant drug treatment in depressive disorders: a systematic review. Lancet 2003;361(9358):653–661. Search PubMed
  6. Discontinuation symptoms Henssler J, Schmidt Y, Schmidt U, Schwarzer G, Bschor T, Baethge C. Incidence of antidepressant discontinuation symptoms: a systematic review and meta-analysis. Lancet Psychiatry 2024;11(7):526–535. Search PubMed
  7. Tapering Horowitz MA, Taylor D. Tapering of SSRI treatment to mitigate withdrawal symptoms. Lancet Psychiatry 2019;6(6):538–546. Royal College of Psychiatrists. Stopping antidepressants. Patient information resource, September 2020. Open
  8. Serotonin syndrome and other side effects Boyer EW, Shannon M. The serotonin syndrome. N Engl J Med 2005;352(11):1112–1120. Search PubMed
  9. ECT UK ECT Review Group. Efficacy and safety of electroconvulsive therapy in depressive disorders: a systematic review and meta-analysis. Lancet 2003;361(9360):799–808. PMID 12642045.
  10. TMS Brunoni AR, Chaimani A, Moffa AH, et al. Repetitive transcranial magnetic stimulation for the acute treatment of major depressive episodes: a systematic review with network meta-analysis. JAMA Psychiatry 2017;74(2):143–152. doi:10.1001/jamapsychiatry.2016.3644.
  11. Esketamine US Food and Drug Administration. FDA approves new nasal spray medication for treatment-resistant depression. Press release, March 2019.
  12. Psilocybin Goodwin GM, Aaronson ST, Alvarez O, et al. Single-dose psilocybin for a treatment-resistant episode of major depression. N Engl J Med 2022;387(18):1637–1648. Search PubMed
  13. Microdosing Szigeti B, Kartner L, Blemings A, et al. Self-blinding citizen science to explore psychedelic microdosing. eLife 2021;10:e62878. doi:10.7554/eLife.62878.
Ch. 14When You Think About Dying7
  1. Safe reporting World Health Organization. Preventing suicide: a resource for media professionals. Update 2023. Geneva: WHO; 2023. ISBN 9789240076846. World Health Organization. LIVE LIFE: an implementation guide for suicide prevention in countries. 2021. Open
  2. Brief crises Simon TR, Swann AC, Powell KE, Potter LB, Kresnow MJ, O'Carroll PW. Characteristics of impulsive suicide attempts and attempters. Suicide Life Threat Behav 2001;32(1 Suppl):49–59. Search PubMed
  3. People kept safe through a crisis Seiden RH. Where are they now? A follow-up study of suicide attempters from the Golden Gate Bridge. Suicide Life Threat Behav 1978;8(4):203–216. Owens D, Horrocks J, House A. Fatal and non-fatal repetition of self-harm: systematic review. Br J Psychiatry 2002;181(3):193–199. Search PubMed
  4. Restricting access to means Zalsman G, Hawton K, Wasserman D, et al. Suicide prevention strategies revisited: 10-year systematic review. Lancet Psychiatry 2016;3(7):646–659. PMID 27289303. Hawton K, Bergen H, Simkin S, et al. Long term effect of reduced pack sizes of paracetamol on poisoning deaths and liver transplant activity in England and Wales: interrupted time series analyses. BMJ 2013;346:f403.
  5. Safety planning Stanley B, Brown GK, Brenner LA, et al. Comparison of the safety planning intervention with follow-up vs usual care of suicidal patients treated in the emergency department. JAMA Psychiatry 2018;75(9):894–900. Stanley B, Brown GK. Safety planning intervention: a brief intervention to mitigate suicide risk. Cogn Behav Pract 2012;19(2):256–264. Search PubMed
  6. Caring letters Motto JA, Bostrom AG. A randomized controlled trial of postcrisis suicide prevention. Psychiatr Serv 2001;52(6):828–833. Search PubMed
  7. The Papageno effect Niederkrotenthaler T, Voracek M, Herberth A, et al. Role of media reports in completed and prevented suicide: Werther v. Papageno effects. Br J Psychiatry 2010;197(3):234–243. Search PubMed
Ch. 15When Someone You Love Is Depressed4
  1. Asking about suicide Dazzi T, Gribble R, Wessely S, Fear NT. Does asking about suicide and related behaviours induce suicidal ideation? What is the evidence? Psychol Med 2014;44(16):3361–3363. PMID 24998511.
  2. Criticism in families Butzlaff RL, Hooley JM. Expressed emotion and psychiatric relapse: a meta-analysis. Arch Gen Psychiatry 1998;55(6):547–552. Mazza C, Formica F, Ferracuti S, et al. High expressed emotion (HEE), assessed using the Five-Minute Speech Sample (FMSS), as a predictor of psychiatric relapse in patients with schizophrenia and major depressive disorder: a meta-analysis and meta-regression. J Clin Med 2022;11(21):6533. doi:10.3390/jcm11216533. PMC9658267.
  3. Mental Health First Aid Morgan AJ, Ross A, Reavley NJ. Systematic review and meta-analysis of Mental Health First Aid training: effects on knowledge, stigma, and helping behaviour. PLoS One 2018;13(5):e0197102. PMC5979014.
  4. Caregiver burden del-Pino-Casado R, Rodríguez Cardosa M, López-Martínez C, Orgeta V. The association between subjective caregiver burden and depressive symptoms in carers of older relatives: a systematic review and meta-analysis. PLoS One 2019;14(5):e0217648. PMC6541277.
Ch. 16Staying Well: Your Plan4
  1. Leftover symptoms Judd LL, Akiskal HS, Maser JD, et al. Major depressive disorder: a prospective study of residual subthreshold depressive symptoms as predictor of rapid relapse. J Affect Disord 1998;50(2–3):97–108. PMID 9858069.
  2. Continuing treatment Geddes et al. 2003 (Chapter 13).
  3. Mindfulness-based cognitive therapy Kuyken W, Warren FC, Taylor RS, et al. Efficacy of mindfulness-based cognitive therapy in prevention of depressive relapse: an individual patient data meta-analysis from randomized trials. JAMA Psychiatry 2016;73(6):565–574. PMID 27119968.
  4. MBCT compared with staying on medication Kuyken W, Hayes R, Barrett B, et al. Effectiveness and cost-effectiveness of mindfulness-based cognitive therapy compared with maintenance antidepressant treatment in the prevention of depressive relapse or recurrence (PREVENT): a randomised controlled trial. Lancet 2015;386(9988):63–73. Search PubMed
BackQuestionnaires at the back of the book1
  1. PHQ-9 Kroenke, Spitzer and Williams 2001 (Chapter 1). Severity bands from the same source.
Cover of Are All These Supplements Actually Doing Anything?

Vol. 12

Are All These Supplements Actually Doing Anything?

Evidence last reviewed October 16, 2026

Ch. 1Are All These Supplements Actually Doing Anything?9
  1. How many adults take supplements Mishra S, Stierman B, Gahche JJ, Potischman N. Dietary supplement use among adults: United States, 2017–2018. NCHS Data Brief no. 399. Hyattsville, MD: National Center for Health Statistics; 2021. doi:10.15620/cdc:101131.
  2. Beta-carotene in male smokers (ATBC) Alpha-Tocopherol, Beta Carotene Cancer Prevention Study Group. The effect of vitamin E and beta carotene on the incidence of lung cancer and other cancers in male smokers. N Engl J Med 1994;330(15):1029–1035.
  3. Beta-carotene and vitamin A (CARET) Omenn GS, Goodman GE, Thornquist MD, et al. Effects of a combination of beta carotene and vitamin A on lung cancer and cardiovascular disease. N Engl J Med 1996;334(18):1150–1155. Search PubMed
  4. Vitamin E and prostate cancer (SELECT) Klein EA, Thompson IM, Tangen CM, et al. Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA 2011;306(14):1549–1556. doi:10.1001/jama.2011.1437.
  5. USPSTF recommendation on vitamins and minerals US Preventive Services Task Force; Mangione CM, Barry MJ, Nicholson WK, et al. Vitamin, mineral, and multivitamin supplementation to prevent cardiovascular disease and cancer: US Preventive Services Task Force recommendation statement. JAMA 2022;327(23):2326–2333. doi:10.1001/jama.2022.8970.
  6. Multivitamins and cancer (PHS II) Gaziano JM, Sesso HD, Christen WG, et al. Multivitamins in the prevention of cancer in men: the Physicians' Health Study II randomized controlled trial. JAMA 2012;308(18):1871–1880. Search PubMed
  7. Multivitamins and heart disease (PHS II) Sesso HD, Christen WG, Bubes V, et al. Multivitamins in the prevention of cardiovascular disease in men: the Physicians' Health Study II randomized controlled trial. JAMA 2012;308(17):1751–1760. doi:10.1001/jama.2012.14805.
  8. Multivitamins and mortality Loftfield E, et al. Multivitamin use and mortality risk in 3 prospective US cohorts. JAMA Netw Open 2024;7(6):e2418729. doi:10.1001/jamanetworkopen.2024.18729.
  9. Folic acid before pregnancy US Preventive Services Task Force; Barry MJ, Nicholson WK, Silverstein M, et al. Folic acid supplementation to prevent neural tube defects: US Preventive Services Task Force reaffirmation recommendation statement. JAMA 2023;330(5):454–459. Search PubMed
Ch. 2Check the Bucket First: When Are You Actually Low?9
  1. Metformin and B12 Aroda VR, Edelstein SL, Goldberg RB, et al. Long-term metformin use and vitamin B12 deficiency in the Diabetes Prevention Program Outcomes Study. J Clin Endocrinol Metab 2016;101(4):1754–1761. doi:10.1210/jc.2015-3754.
  2. B12 monitoring with metformin American Diabetes Association. Standards of Care in Diabetes (updated annually).
  3. Acid reducers and B12 Lam JR, Schneider JL, Zhao W, Corley DA. Proton pump inhibitor and histamine 2 receptor antagonist use and vitamin B12 deficiency. JAMA 2013;310(22):2435–2442. Search PubMed
  4. B12 in older adults; nerve symptoms without anemia NIH Office of Dietary Supplements. Vitamin B12: Fact Sheet for Health Professionals.
  5. After weight-loss surgery Mechanick JI, Apovian C, Brethauer S, et al. Clinical practice guidelines for the perioperative nutrition, metabolic, and nonsurgical support of patients undergoing bariatric procedures – 2019 update. Surg Obes Relat Dis 2020;16(2):175–247. doi:10.1016/j.soard.2019.10.025.
  6. Vitamin D screening Krist AH, Davidson KW, Mangione CM, et al. Screening for vitamin D deficiency in adults: US Preventive Services Task Force recommendation statement. JAMA 2021;325(14):1436–1442. Search PubMed
  7. Vitamin D guideline Demay MB, Pittas AG, Bikle DD, et al. Vitamin D for the prevention of disease: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2024;109(8):1907–1947. doi:10.1210/clinem/dgae290.
  8. Hair mineral analysis Seidel S, Kreutzer R, Smith D, McNeel S, Gilliss D. Assessment of commercial laboratories performing hair mineral analysis. JAMA 2001;285(1):67–72. Search PubMed
  9. IV micronutrient therapy Ali A, Njike VY, Northrup V, et al. Intravenous micronutrient therapy (Myers' Cocktail) for fibromyalgia: a placebo-controlled pilot study. J Altern Complement Med 2009;15(3):247–257. Search PubMed
Ch. 3Is What's on the Label in the Bottle?6
  1. How supplements are regulated in the United States; quality seals NIH Office of Dietary Supplements. Dietary Supplements: What You Need to Know. Dietary Supplement Health and Education Act of 1994.
  2. Food supplements in the European Union Directive 2002/46/EC; Regulation (EC) No 1924/2006; Food Safety Authority of Ireland, Food Supplements.
  3. Melatonin gummies Cohen PA, Avula B, Wang YH, Katragunta K, Khan I. Quantity of melatonin and CBD in melatonin gummies sold in the US. JAMA 2023;329(16):1401–1402. Search PubMed
  4. Undeclared drugs in supplements Tucker J, Fischer T, Upjohn L, Mazzera D, Kumar M. Unapproved pharmaceutical ingredients included in dietary supplements associated with US Food and Drug Administration warnings. JAMA Netw Open 2018;1(6):e183337. Search PubMed
  5. Banned drugs after recalls Cohen PA, Maller G, DeSouza R, Neal-Kababick J. Presence of banned drugs in dietary supplements following FDA recalls. JAMA 2014;312(16):1691–1693. doi:10.1001/jama.2014.10308.
  6. Emergency visits Geller AI, Shehab N, Weidle NJ, et al. Emergency department visits for adverse events related to dietary supplements. N Engl J Med 2015;373(16):1531–1540. doi:10.1056/NEJMsa1504267.
Ch. 4Decoding the Label4
  1. Structure/function claims US Food and Drug Administration. Structure/Function Claims. Code of Federal Regulations, 21 CFR 101.93.
  2. Proprietary blends; daily values US Food and Drug Administration. Small Entity Compliance Guide: Statement of Identity, Nutrition Labeling, and Ingredient Labeling of Dietary Supplements. 21 CFR 101.36.
  3. Health claims in Europe Regulation (EC) No 1924/2006.
  4. Detox products Klein AV, Kiat H. Detox diets for toxin elimination and weight management: a critical review of the evidence. J Hum Nutr Diet 2015;28(6):675–686. doi:10.1111/jhn.12286.
Ch. 5Multivitamins: Insurance or Wasted Money?6
  1. PHS II See Chapter 1 (Gaziano et al. 2012; Sesso et al. 2012).
  2. COSMOS, cancer and heart disease Sesso HD, Rist PM, Aragaki AK, et al. Multivitamins in the prevention of cancer and cardiovascular disease: the COSMOS randomized clinical trial. Am J Clin Nutr 2022;115(6):1501–1510. doi:10.1093/ajcn/nqac056.
  3. COSMOS, memory Vyas CM, Manson JE, Sesso HD, et al. Effect of multivitamin-mineral supplementation versus placebo on cognitive function: results from the clinic subcohort of the COSMOS randomized clinical trial and meta-analysis of 3 cognitive studies within COSMOS. Am J Clin Nutr 2024;119(3):692–701. Baker LD, Manson JE, Rapp SR, et al. Alzheimers Dement 2023;19(4):1308–1319. Search PubMed
  4. Folic acid and neural tube defects See Chapter 8 (MRC Vitamin Study 1991; USPSTF 2023).
  5. After weight-loss surgery See Chapter 2 (Mechanick et al. 2020).
  6. Vitamin A in pregnancy Rothman KJ, Moore LL, Singer MR, et al. Teratogenicity of high vitamin A intake. N Engl J Med 1995;333(21):1369–1373. Search PubMed
Ch. 6Vitamin D on Trial9
  1. VITAL, cancer and heart disease Manson JE, Cook NR, Lee IM, et al. Vitamin D supplements and prevention of cancer and cardiovascular disease. N Engl J Med 2019;380(1):33–44. Search PubMed
  2. VITAL, fractures LeBoff MS, Chou SH, Ratliff KA, et al. Supplemental vitamin D and incident fractures in midlife and older adults. N Engl J Med 2022;387(4):299–309. Search PubMed
  3. D-Health Neale RE, Baxter C, Romero BD, et al. The D-Health Trial: a randomised controlled trial of the effect of vitamin D on mortality. Lancet Diabetes Endocrinol 2022;10(2):120–128. Search PubMed
  4. Vitamin D and bone health Bolland MJ, Grey A, Avenell A. Effects of vitamin D supplementation on musculoskeletal health: a systematic review, meta-analysis, and trial sequential analysis. Lancet Diabetes Endocrinol 2018;6(11):847–858. Search PubMed
  5. Vitamin D with calcium, fractures Avenell A, Mak JCS, O'Connell DL. Vitamin D and vitamin D analogues for preventing fractures in post-menopausal women and older men. Cochrane Database Syst Rev 2014;(4):CD000227. Search PubMed
  6. Very high yearly dose Sanders KM, Stuart AL, Williamson EJ, et al. Annual high-dose oral vitamin D and falls and fractures in older women: a randomized controlled trial. JAMA 2010;303(18):1815–1822. Search PubMed
  7. Cancer incidence and mortality Keum N, Lee DH, Greenwood DC, Manson JE, Giovannucci E. Vitamin D supplementation and total cancer incidence and mortality: a meta-analysis of randomized controlled trials. Ann Oncol 2019;30(5):733–743. doi:10.1093/annonc/mdz059.
  8. Respiratory infections Jolliffe DA, Camargo CA, Sluyter JD, et al. Vitamin D supplementation to prevent acute respiratory infections: systematic review and meta-analysis of stratified aggregate data. Lancet Diabetes Endocrinol 2025;13(4):307–320. doi:10.1016/S2213-8587(24)00348-600348-6).
  9. Guideline, doses and adults 75 and over See Chapter 2 (Demay et al. 2024).
Ch. 7Fish Oil: Heart, Brain, and a Surprise9
  1. Eating fish Rimm EB, Appel LJ, Chiuve SE, et al. Seafood long-chain n-3 polyunsaturated fatty acids and cardiovascular disease: a science advisory from the American Heart Association. Circulation 2018;138(1):e35–e47. doi:10.1161/CIR.0000000000000574.
  2. VITAL, omega-3 Manson JE, Cook NR, Lee IM, et al. Marine n-3 fatty acids and prevention of cardiovascular disease and cancer. N Engl J Med 2019;380(1):23–32. Search PubMed
  3. ASCEND ASCEND Study Collaborative Group. Effects of n−3 fatty acid supplements in diabetes mellitus. N Engl J Med 2018;379(16):1540–1550.
  4. Cochrane review Abdelhamid AS, Brown TJ, Brainard JS, et al. Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease. Cochrane Database Syst Rev 2020;3(3):CD003177. Search PubMed
  5. REDUCE-IT Bhatt DL, Steg PG, Miller M, et al. Cardiovascular risk reduction with icosapent ethyl for hypertriglyceridemia. N Engl J Med 2019;380(1):11–22. Search PubMed
  6. STRENGTH Nicholls SJ, Lincoff AM, Garcia M, et al. Effect of high-dose omega-3 fatty acids vs corn oil on major adverse cardiovascular events in patients at high cardiovascular risk: the STRENGTH randomized clinical trial. JAMA 2020;324(22):2268–2280. Search PubMed
  7. Atrial fibrillation Gencer B, Djousse L, Al-Ramady OT, Cook NR, Manson JE, Albert CM. Effect of long-term marine omega-3 fatty acids supplementation on the risk of atrial fibrillation in randomized controlled trials of cardiovascular outcomes: a systematic review and meta-analysis. Circulation 2021;144(25):1981–1990. doi:10.1161/CIRCULATIONAHA.121.055654.
  8. Pregnancy Middleton P, Gomersall JC, Gould JF, et al. Omega-3 fatty acid addition during pregnancy. Cochrane Database Syst Rev 2018;11:CD003402. doi:10.1002/14651858.CD003402.pub3.
  9. Memory Sydenham E, Dangour AD, Lim WS. Omega 3 fatty acid for the prevention of cognitive decline and dementia. Cochrane Database Syst Rev 2012;(6):CD005379. Search PubMed
Ch. 8Four That Can Save You: Folate, Iron, B12, Calcium10
  1. Folic acid trial Wald N, Sneddon J; MRC Vitamin Study Research Group. Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. Lancet 1991;338(8760):131–137.
  2. Folic acid recommendation See Chapter 1 (USPSTF 2023).
  3. Iron deficiency anemia Snook J, Bhala N, Beales ILP, et al. British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults. Gut 2021;70(11):2030–2051. doi:10.1136/gutjnl-2021-325210.
  4. Alternate-day iron Stoffel NU, Zeder C, Brittenham GM, Moretti D, Zimmermann MB. Iron absorption from supplements is greater with alternate day than with consecutive day dosing in iron-deficient anemic women. Haematologica 2020;105(5):1232–1239. doi:10.3324/haematol.2019.220830.
  5. Iron and young children US Food and Drug Administration. Dietary Supplement Labeling Guide, Chapter VIII. 21 CFR 101.17(e).
  6. B12 for vegans Melina V, Craig W, Levin S. Position of the Academy of Nutrition and Dietetics: vegetarian diets. J Acad Nutr Diet 2016;116(12):1970–1980. doi:10.1016/j.jand.2016.09.025.
  7. B12 safety See Chapter 2 (NIH Office of Dietary Supplements).
  8. Calcium and fractures Bolland MJ, Leung W, Tai V, et al. Calcium intake and risk of fracture: systematic review. BMJ 2015;351:h4580. Tai V, Leung W, Grey A, Reid IR, Bolland MJ. Calcium intake and bone mineral density: systematic review and meta-analysis. BMJ 2015;351:h4183. Search PubMed
  9. Calcium and heart attack Bolland MJ, Avenell A, Baron JA, et al. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. BMJ 2010;341:c3691. doi:10.1136/bmj.c3691.
  10. Calcium with vitamin D and kidney stones (WHI) Jackson RD, LaCroix AZ, Gass M, et al. Calcium plus vitamin D supplementation and the risk of fractures. N Engl J Med 2006;354(7):669–683. Search PubMed
Ch. 9"Immune Boosters": Vitamin C, Zinc, and the Common Cold8
  1. Vitamin C Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev 2013;(1):CD000980. Search PubMed
  2. Zinc Nault D, Machingo TA, Shipper AG, et al. Zinc for prevention and treatment of the common cold. Cochrane Database Syst Rev 2024;5(5):CD014914. doi:10.1002/14651858.CD014914.pub2.
  3. Zinc safety NIH Office of Dietary Supplements. Zinc: Fact Sheet for Health Professionals.
  4. Zinc nasal products US Food and Drug Administration warning on intranasal zinc products, June 2009.
  5. Echinacea Karsch-Völk M, Barrett B, Kiefer D, Bauer R, Ardjomand-Woelkart K, Linde K. Echinacea for preventing and treating the common cold. Cochrane Database Syst Rev 2014;(2):CD000530. doi:10.1002/14651858.CD000530.pub3.
  6. Elderberry Wieland LS, Piechotta V, Feinberg T, et al. Elderberry for prevention and treatment of viral respiratory illnesses: a systematic review. BMC Complement Med Ther 2021;21(1):112. Search PubMed
  7. Sleep and colds Prather AA, Janicki-Deverts D, Hall MH, Cohen S. Behaviorally assessed sleep and susceptibility to the common cold. Sleep 2015;38(9):1353–1359. Search PubMed
  8. Vitamin D and respiratory infections See Chapter 6 (Jolliffe et al. 2025).
Ch. 10Natural Isn't Safe by Default: Herbal Pills6
  1. Liver injury from supplements Navarro VJ, Barnhart H, Bonkovsky HL, et al. Liver injury from herbals and dietary supplements in the U.S. Drug-Induced Liver Injury Network. Hepatology 2014;60(4):1399–1408. doi:10.1002/hep.27317.
  2. Green tea extract EFSA Panel on Food Additives and Nutrient Sources added to Food. Scientific opinion on the safety of green tea catechins. EFSA Journal 2018;16(4):5239. Commission Regulation (EU) 2022/2340.
  3. St John's wort National Center for Complementary and Integrative Health (NIH). St. John's Wort.
  4. Turmeric National Center for Complementary and Integrative Health (NIH). Turmeric.
  5. Ashwagandha National Center for Complementary and Integrative Health (NIH). Ashwagandha.
  6. Ginkgo (GEM trial) National Center for Complementary and Integrative Health (NIH). Ginkgo. DeKosky ST, Williamson JD, Fitzpatrick AL, et al. Ginkgo biloba for prevention of dementia: a randomized controlled trial. JAMA 2008;300(19):2253–2262. Search PubMed
Ch. 11The New Wave: NAD+, Creatine, Protein Powder and "Smart Pills"5
  1. NMN in humans Song Q, Zhou X, Xu K, et al. The safety and antiaging effects of nicotinamide mononucleotide in human clinical trials: an update. Adv Nutr 2023;14(6):1416–1435. Search PubMed
  2. Creatine in older adults Chilibeck PD, Kaviani M, Candow DG, Zello GA. Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis. Open Access J Sports Med 2017;8:213–226. doi:10.2147/OAJSM.S123529.
  3. Creatine safety Kreider RB, Kalman DS, Antonio J, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr 2017;14:18. doi:10.1186/s12970-017-0173-z.
  4. Protein supplements Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med 2018;52(6):376–384. Search PubMed
  5. "Smart pills" Cohen PA, Avula B, Wang YH, Zakharevich I, Khan I. Five unapproved drugs found in cognitive enhancement supplements. Neurol Clin Pract 2021;11(3):e303–e307. doi:10.1212/CPJ.0000000000000960.
Ch. 12Stacking, Megadoses and Drug Interactions7
  1. Medicines and supplements in older adults Qato DM, Wilder J, Schumm LP, Gillet V, Alexander GC. Changes in prescription and over-the-counter medication and dietary supplement use among older adults in the United States, 2005 vs 2011. JAMA Intern Med 2016;176(4):473–482. Search PubMed
  2. Vitamin B6 upper safe level Turck D, Bohn T, Castenmiller J, et al. (EFSA Panel on Nutrition, Novel Foods and Food Allergens). Scientific opinion on the tolerable upper intake level for vitamin B6. EFSA Journal 2023;21(5):8006. doi:10.2903/j.efsa.2023.8006.
  3. Vitamin B6 in Australia Therapeutic Goods Administration (Australia). Health supplements containing vitamin B6 can cause peripheral neuropathy (safety alert).
  4. Vitamin K and warfarin See Chapter 3 (NIH Office of Dietary Supplements).
  5. Ginkgo and blood thinners See Chapter 10 (NCCIH, Ginkgo).
  6. Biotin and lab tests US Food and Drug Administration. The FDA warns that biotin may interfere with lab tests: FDA safety communication, November 28, 2017.
  7. Upper safe levels NIH Office of Dietary Supplements fact sheets: Vitamin A and Carotenoids; Vitamin D; Vitamin B6; Zinc; Iron.
Ch. 13Keep, Drop, or Ask1
  1. The ten key claims See the sources for Chapters 1, 2, 5, 6, 7, 8, 9, 10 and 12.
BackWorksheets at the back of the book3
  1. Groups at risk of running low See Chapters 2 and 8 (Aroda et al. 2016; Lam et al. 2013; Mechanick et al. 2020; Melina et al. 2016; Snook et al. 2021).
  2. Upper safe levels on the Four-Filter Worksheet See Chapter 12 (NIH Office of Dietary Supplements fact sheets; Turck et al., EFSA 2023).
  3. Drug interactions on the checklist for your doctor or pharmacist See Chapters 10 and 12 (NCCIH; US Food and Drug Administration, biotin safety communication 2017).
Cover of I Lost Weight on a Shot. Now What?

Vol. 14

I Lost Weight on a Shot. Now What?

Evidence last reviewed October 20, 2026

Ch. 1I Lost Weight on a Shot. Now What?9
  1. Semaglutide for weight loss (STEP 1) Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med 2021;384(11):989–1002. doi:10.1056/NEJMoa2032183.
  2. Tirzepatide for weight loss (SURMOUNT-1) Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide once weekly for the treatment of obesity. N Engl J Med 2022;387(3):205–216. doi:10.1056/NEJMoa2206038.
  3. Semaglutide and heart disease (SELECT) Lincoff AM, Brown-Frandsen K, Colhoun HM, et al. Semaglutide and cardiovascular outcomes in obesity without diabetes. N Engl J Med 2023;389(24):2221–2232. doi:10.1056/NEJMoa2307563.
  4. Oral semaglutide approval US Food and Drug Administration approval of the Wegovy pill (oral semaglutide 25 mg), December 22, 2025.
  5. Orforglipron approval US Food and Drug Administration approval of Foundayo (orforglipron), April 1, 2026.
  6. Clinical obesity Rubino F, Cummings DE, Eckel RH, et al. Definition and diagnostic criteria of clinical obesity. Lancet Diabetes Endocrinol 2025;13(3):221–262. Search PubMed
  7. Regain after stopping semaglutide (STEP 1 extension) Wilding JPH, Batterham RL, Davies M, et al. Weight regain and cardiometabolic effects after withdrawal of semaglutide: the STEP 1 trial extension. Diabetes Obes Metab 2022;24(8):1553–1564. doi:10.1111/dom.14725.
  8. Regain after stopping weight-loss medicines West S, Koutoukidis DA, Jebb SA, et al. Weight regain after cessation of medication for weight management: systematic review and meta-analysis. BMJ 2026. PMID 41500720.
  9. The 30-second chair stand Jones CJ, Rikli RE, Beam WC. A 30-s chair-stand test as a measure of lower body strength in community-residing older adults. Res Q Exerc Sport 1999;70(2):113–119. Search PubMed
Ch. 2The Scale Went Down. What Went With It?3
  1. Body composition with semaglutide (STEP 1, DXA substudy) Wilding JPH, et al. N Engl J Med 2021;384(11):989–1002. doi:10.1056/NEJMoa2032183. See Chapter 1.
  2. Is muscle loss clinically relevant? Conte C, Hall KD, Klein S. Is weight loss–induced muscle mass loss clinically relevant? JAMA 2024. PMID 38829659.
  3. Muscle on GLP-1 medicines: adaptive or harmful? Linge J, Birkenfeld AL, Neeland IJ. Muscle mass and glucagon-like peptide-1 receptor agonists: adaptive or maladaptive response to weight loss? Circulation 2024;150. doi:10.1161/CIRCULATIONAHA.124.067676.
Ch. 3Eating When You're Not Hungry3
  1. Nutrition on GLP-1 medicines Mozaffarian D, Agarwal M, Aggarwal M, et al. Nutritional priorities to support GLP-1 therapy for obesity: a joint Advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society. Published simultaneously in Am J Clin Nutr, Obesity, Obesity Pillars and Am J Lifestyle Med, 2025. PMID 40450457.
  2. Gallbladder disease with GLP-1 medicines He L, Wang J, Ping F, et al. Association of glucagon-like peptide-1 receptor agonist use with risk of gallbladder and biliary diseases: a systematic review and meta-analysis of randomized clinical trials. JAMA Intern Med 2022;182(5):513–519. Search PubMed
  3. Gallstones on the Wegovy label US Food and Drug Administration. Wegovy (semaglutide) prescribing information, revised March 2026.
Ch. 4A Chair, a Pair of Weights, Twice a Week4
  1. Strength training while dieting Sardeli AV, Komatsu TR, Mori MA, Gáspari AF, Chacon-Mikahil MPT. Resistance training prevents muscle loss induced by caloric restriction in obese elderly individuals: a systematic review and meta-analysis. Nutrients 2018;10(4):423. doi:10.3390/nu10040423.
  2. Exercise, liraglutide or both (S-LITE) Lundgren JR, Janus C, Jensen SBK, et al. Healthy weight loss maintenance with exercise, liraglutide, or both combined. N Engl J Med 2021;384(18):1719–1730. PMID 33951361.
  3. One year after stopping (S-LITE follow-up) Jensen SBK, Blond MB, Sandsdal RM, et al. Healthy weight loss maintenance with exercise, GLP-1 receptor agonist, or both combined followed by one year without treatment: a post-treatment analysis of a randomised placebo-controlled trial. eClinicalMedicine 2024;69:102475. doi:10.1016/j.eclinm.2024.102475.
  4. Physical activity guidelines Bull FC, Al-Ansari SS, Biddle S, et al. World Health Organization 2020 guidelines on physical activity and sedentary behaviour. Br J Sports Med 2020;54(24):1451–1462. Search PubMed
Ch. 5The 2 a.m. Questions9
  1. Side effects, pancreatitis, low blood sugar, kidney injury, anesthesia, pregnancy, thyroid warning US Food and Drug Administration. Wegovy (semaglutide) injection and tablets, prescribing information, revised March 2026.
  2. Serious digestive events Sodhi M, Rezaeianzadeh R, Kezouh A, Etminan M. Risk of gastrointestinal adverse events associated with glucagon-like peptide-1 receptor agonists for weight loss. JAMA 2023;330(18):1795–1797. doi:10.1001/jama.2023.19574.
  3. GLP-1 medicines around surgery American Society of Anesthesiologists, American Gastroenterological Association, American Society for Metabolic and Bariatric Surgery, International Society of Perioperative Care of Patients with Obesity, Society of American Gastrointestinal and Endoscopic Surgeons. Multisociety clinical practice guidance on GLP-1 receptor agonists in the perioperative period, October 29, 2024.
  4. Tirzepatide and birth control pills Eli Lilly and Company. Zepbound (tirzepatide) prescribing information: oral hormonal contraceptives.
  5. Suicidal thoughts: European review European Medicines Agency, Pharmacovigilance Risk Assessment Committee (PRAC). Meeting highlights, April 8–11, 2024.
  6. Suicidal thoughts: US label change US Food and Drug Administration. Request to remove the suicidal behavior and ideation warning from GLP-1 receptor agonist labels, January 2026.
  7. NAION European Medicines Agency, Pharmacovigilance Risk Assessment Committee (PRAC). PRAC concludes eye condition NAION is a very rare side effect of semaglutide medicines Ozempic, Rybelsus and Wegovy, June 6, 2025.
  8. Thyroid cancer: Nordic study Pasternak B, Wintzell V, Hviid A, et al. Glucagon-like peptide 1 receptor agonist use and risk of thyroid cancer: Scandinavian cohort study. BMJ 2024. doi:10.1136/bmj-2023-078225.
  9. Thyroid cancer: French study Bezin J, Gouverneur A, Pénichon M, et al. GLP-1 receptor agonists and the risk of thyroid cancer. Diabetes Care 2023;46(2):384–390. Search PubMed
Ch. 6365 Days After the Last Dose5
  1. Stopping semaglutide (STEP 4) Rubino D, Abrahamsson N, Davies M, et al. Effect of continued weekly subcutaneous semaglutide vs placebo on weight loss maintenance in adults with overweight or obesity: the STEP 4 randomized clinical trial. JAMA 2021;325(14):1414–1425. Search PubMed
  2. Stopping tirzepatide (SURMOUNT-4) Aronne LJ, Sattar N, Horn DB, et al. Continued treatment with tirzepatide for maintenance of weight reduction in adults with obesity: the SURMOUNT-4 randomized clinical trial. JAMA 2024;331(1):38–48. Search PubMed
  3. Pace of regain and return of cardiometabolic markers West S, et al. BMJ 2026. PMID 41500720. See Chapter 1.
  4. STEP 1 extension Wilding JPH, et al. Diabetes Obes Metab 2022;24(8):1553–1564. doi:10.1111/dom.14725. See Chapter 1.
  5. Half-life of semaglutide US Food and Drug Administration. Wegovy (semaglutide) prescribing information, revised March 2026.
Ch. 7Stop, Step Down, or Stay On?5
  1. Staying on the medicine Rubino D, et al. JAMA 2021;325(14):1414–1425; Aronne LJ, et al. JAMA 2024;331(1):38–48. See Chapter 6.
  2. WHO guideline World Health Organization. Guideline on the use of GLP-1 medicines in treating obesity in adults, December 1, 2025.
  3. Switching to a pill (ATTAIN-MAINTAIN) Aronne LJ, Horn DB, le Roux CW, et al. Orforglipron for maintenance of body weight reduction: the double-blind, randomized phase 3b ATTAIN-MAINTAIN trial. Nat Med 2026. doi:10.1038/s41591-026-04386-7 (published May 12, 2026).
  4. Tapering Gudbergsen H, et al. (Embla). Conference report on tapering semaglutide in patients of a digital weight-loss clinic (real-world cohort; 54 people tapered to zero), European Congress on Obesity, Venice, 2024; abstract in the ECO 2024 abstract supplement, Obesity Facts (Karger). Not peer-reviewed; no comparison group.
  5. Generic semaglutide Health Canada approvals of generic semaglutide (Dr Reddy's, Apotex), April–May 2026; launches in India, March 2026.
Ch. 8The 12-Week Handover4
  1. The National Weight Control Registry Wing RR, Phelan S. Long-term weight loss maintenance. Am J Clin Nutr 2005;82(1 Suppl):222S–225S. doi:10.1093/ajcn/82.1.222S. PMID 16002825.
  2. Exercise after stopping Jensen SBK, et al. eClinicalMedicine 2024. See Chapter 4.
  3. Daily weighing and self-regulation (STOP Regain) Wing RR, Tate DF, Gorin AA, Raynor HA, Fava JL. A self-regulation program for maintenance of weight loss. N Engl J Med 2006;355(15):1563–1571. Search PubMed
  4. Self-weighing Zheng Y, Klem ML, Sereika SM, Danford CA, Ewing LJ, Burke LE. Self-weighing in weight management: a systematic literature review. Obesity (Silver Spring) 2015;23(2):256–265. PMID 25521523.
Ch. 9Real, Compounded, Counterfeit4
  1. Counterfeit semaglutide World Health Organization. Medical Product Alert N°2/2024: Falsified OZEMPIC (semaglutide), June 19, 2024; and WHO issues warning on falsified medicines used for diabetes treatment and weight loss, June 20, 2024.
  2. Dosing errors with compounded semaglutide US Food and Drug Administration. Alert on dosing errors associated with compounded injectable semaglutide products, July 26, 2024.
  3. Generic semaglutide See Chapter 7.
  4. Access and equity World Health Organization guideline, December 1, 2025. See Chapter 7.
Ch. 10Who Shouldn't Be on It4
  1. Contraindications, pregnancy, retinopathy, type 1 diabetes, heart rate US Food and Drug Administration. Wegovy (semaglutide) prescribing information, revised March 2026.
  2. Retinopathy in people with type 2 diabetes (SUSTAIN-6) Marso SP, Bain SC, Consoli A, et al. Semaglutide and cardiovascular outcomes in patients with type 2 diabetes. N Engl J Med 2016;375(19):1834–1844. Search PubMed
  3. Who the WHO guideline covers World Health Organization guideline, December 1, 2025. See Chapter 7.
  4. Eating disorders No clinical studies were found; the chapter draws on published case reports described by clinicians and does not assign a label.
Ch. 11New Body, Same Old Brain4
  1. Semaglutide and alcohol Hendershot CS, Bremmer MP, Paladino MB, et al. Once-weekly semaglutide in adults with alcohol use disorder: a randomized clinical trial. JAMA Psychiatry 2025;82(4):395–405. doi:10.1001/jamapsychiatry.2024.4789.
  2. Medicine plus behavior change Wadden TA, Berkowitz RI, Womble LG, et al. Randomized trial of lifestyle modification and pharmacotherapy for obesity. N Engl J Med 2005;353(20):2111–2120. PMID 16291981.
  3. Behavioral support doesn't slow regain West S, et al. BMJ 2026. PMID 41500720. See Chapter 1.
  4. Weight stigma Rubino F, Puhl RM, Cummings DE, et al. Joint international consensus statement for ending stigma of obesity. Nat Med 2020;26(4):485–497. PMID 32127716.
Ch. 12Keep the Muscle, Keep the Results1
  1. The six key claims See the sources for Chapters 1, 2, 4, 6 and 7.
BackWorksheets at the back of the book6
  1. Three numbers and the chair stand See Chapters 1 and 2 (Jones et al. 1999).
  2. Protein by hand See Chapter 3 (Mozaffarian et al. 2025).
  3. 12-week strength program See Chapter 4 (Bull et al. 2020; Sardeli et al. 2018).
  4. Three-level side-effect chart See Chapter 5 (Wegovy and Zepbound prescribing information; EMA PRAC 2024 and 2025).
  5. Handover plan and red line See Chapter 8 (Wing et al. 2006; Wing and Phelan 2005).
  6. Twelve check questions See Chapter 10 (Wegovy prescribing information; WHO 2025).
Cover of Do I Really Need to Detox After the Holidays?

Vol. 15

Do I Really Need to Detox After the Holidays?

Evidence last reviewed October 22, 2026

Ch. 1Do I Really Need to Detox After the Holidays?3
  1. Detox diets: a critical review Klein AV, Kiat H. Detox diets for toxin elimination and weight management: a critical review of the evidence. J Hum Nutr Diet 2015;28(6):675–686. doi:10.1111/jhn.12286.
  2. Asking companies to name the toxin Sense About Science. The Detox Dossier. London: Sense About Science; 2009.
  3. How the liver handles alcohol National Institute on Alcohol Abuse and Alcoholism (NIAAA). Alcohol metabolism: an update. Alcohol Alert No. 72; 2007.
Ch. 2What the Cleanse Is Really Selling8
  1. Detox diets and weight Klein and Kiat 2015. See Chapter 1.
  2. Kidney failure after a smoothie cleanse Makkapati S, D'Agati VD, Balsam L. "Green smoothie cleanse" causing acute oxalate nephropathy. Am J Kidney Dis 2018;71(2):281–286. PMID 29203127.
  3. Kidney injury after a juice diet Oxalate nephropathy: a case report of acute kidney injury due to juice diet. Cureus 2023. PMCID PMC10821746.
  4. Milk thistle Rambaldi A, Jacobs BP, Gluud C. Milk thistle for alcoholic and/or hepatitis B or C virus liver diseases. Cochrane Database Syst Rev 2007;(4):CD003620. Search PubMed
  5. Activated charcoal in poisoning American Academy of Clinical Toxicology; European Association of Poisons Centres and Clinical Toxicologists. Position paper: single-dose activated charcoal. Clin Toxicol (Phila) 2005;43(2):61–87.
  6. Hangover remedies, including charcoal Roberts et al. 2022. See Chapter 5.
  7. Colon cleansing Acosta RD, Cash BD. Clinical effects of colonic cleansing for general health promotion: a systematic review. Am J Gastroenterol 2009;104(11):2830–2836. Search PubMed
  8. Supplements are not tested like medicines US Food and Drug Administration. Dietary Supplement Health and Education Act of 1994. See also Volume 12 of this series.
Ch. 3The Real Toxins12
  1. No safe blood lead level World Health Organization. WHO guideline for the clinical management of exposure to lead. Geneva: WHO; 2021.
  2. The decline in blood lead after leaded gasoline Pirkle JL, Brody DJ, Gunter EW, et al. The decline in blood lead levels in the United States: the National Health and Nutrition Examination Surveys (NHANES). JAMA 1994;272(4):284–291. Search PubMed
  3. Secondhand smoke US Department of Health and Human Services. The health consequences of involuntary exposure to tobacco smoke: a report of the Surgeon General. Atlanta: 2006.
  4. Carbon monoxide alarms and prevention Centers for Disease Control and Prevention. Carbon monoxide poisoning: prevention guidance. 2024.
  5. Eating fish in pregnancy and childhood US Food and Drug Administration, US Environmental Protection Agency. Advice about eating fish. 2017, updated 2021.
  6. Cooking rice to remove arsenic Menon M, Dong W, Chen X, Hufton J, Rhodes EJ. Improved rice cooking approach to maximise arsenic removal while preserving nutrient elements. Sci Total Environ 2021;755:143341. Search PubMed
  7. Microplastics in artery plaque Marfella R, Prattichizzo F, Sardu C, et al. Microplastics and nanoplastics in atheromas and cardiovascular events. N Engl J Med 2024;390(10):900–910. Search PubMed
  8. PFAS and health National Academies of Sciences, Engineering, and Medicine. Guidance on PFAS exposure, testing, and clinical follow-up. Washington, DC: National Academies Press; 2022.
  9. Blood and plasma donation lower PFAS Gasiorowski R, Forbes MK, Silver G, et al. Effect of plasma and blood donations on levels of perfluoroalkyl and polyfluoroalkyl substances in firefighters in Australia: a randomized clinical trial. JAMA Netw Open 2022;5(4):e226257. Search PubMed
  10. Detox products and real toxins Klein AV, Kiat H. Detox diets for toxin elimination and weight management: a critical review of the evidence. J Hum Nutr Diet 2015;28(6):675–686. doi:10.1111/jhn.12286.
  11. Provoked urine metal testing American College of Medical Toxicology. Position statement on post-chelator challenge urinary metal testing. J Med Toxicol 2010;6(1):74–75.
  12. Deaths from chelation therapy Centers for Disease Control and Prevention. Deaths associated with hypocalcemia from chelation therapy: Texas, Pennsylvania, and Oregon, 2003–2005. MMWR 2006;55(8):204–207.
Ch. 4Thirty-Nine Days on One Page7
  1. Holiday weight gain: systematic review Winter holidays and their impact on eating behavior: a systematic review. Nutrients 2023;15(19):4201.
  2. Holiday weight gain: review Díaz-Zavala RG, Castro-Cantú MF, Valencia ME, et al. Effect of the holiday season on weight gain: a narrative review. J Nutr Metab 2017;2017:2085136. doi:10.1155/2017/2085136.
  3. Holiday weight gain that stays Yanovski JA, Yanovski SZ, Sovik KN, et al. A prospective study of holiday weight gain. N Engl J Med 2000;342(12):861–867. Search PubMed
  4. Holiday weight gain in three countries Helander EE, Wansink B, Chin A. Weight gain over the holidays in three countries. N Engl J Med 2016;375(12):1200–1202. Search PubMed
  5. Heart attacks at Christmas in Sweden Mohammad MA, Karlsson S, Haddad J, et al. Christmas, national holidays, sport events, and time factors as triggers of acute myocardial infarction: SWEDEHEART observational study 1998–2013. BMJ 2018;363:k4811. Search PubMed
  6. Cardiac deaths around the holidays in the US Phillips DP, Jarvinen JR, Abramson IS, Phillips RR. Cardiac mortality is higher around Christmas and New Year's than at any other time. Circulation 2004;110(25):3781–3788. Search PubMed
  7. Holiday heart syndrome Ettinger PO, Wu CF, De La Cruz C Jr, et al. Arrhythmias and the "Holiday Heart": alcohol-associated cardiac rhythm disorders. Am Heart J 1978;95(5):555–562. PMID 636996.
Ch. 5The Morning After7
  1. Hangover cures: systematic review (2022) Roberts E, Smith R, Hotopf M, Drummond C. The efficacy and tolerability of pharmacologically active interventions for alcohol-induced hangover symptomatology: a systematic review of the evidence from randomised placebo-controlled trials. Addiction 2022;117(8):2149–2163. PMID 34972259.
  2. Hangover cures: systematic review (2005) Pittler MH, Verster JC, Ernst E. Interventions for preventing or treating alcohol hangover: systematic review of randomised controlled trials. BMJ 2005;331(7531):1515–1518. Search PubMed
  3. Defining a hangover Verster JC, Scholey A, van de Loo AJAE, et al. Updating the definition of the alcohol hangover. J Clin Med 2020;9(3):823. Search PubMed
  4. How hangovers happen Palmer E, Tyacke R, Sastre M, et al. Alcohol hangover: underlying biochemical, inflammatory and neurochemical mechanisms. Alcohol Alcohol 2019;54(3):196–203. Search PubMed
  5. Dark and clear drinks Rohsenow DJ, Howland J, Arnedt JT, et al. Intoxication with bourbon versus vodka: effects on hangover, sleep, and next-day neurocognitive performance in young adults. Alcohol Clin Exp Res 2010;34(3):509–518. Search PubMed
  6. Paracetamol, anti-inflammatory painkillers and alcohol US Food and Drug Administration. Over-the-counter labeling for acetaminophen and nonsteroidal anti-inflammatory drugs (alcohol warnings).
  7. Alcohol poisoning National Institute on Alcohol Abuse and Alcoholism (NIAAA). Understanding the dangers of alcohol overdose.
Ch. 6The Heart on New Year's Eve7
  1. Stopping alcohol in atrial fibrillation Voskoboinik A, Kalman JM, De Silva A, et al. Alcohol abstinence in drinkers with atrial fibrillation. N Engl J Med 2020;382(1):20–28. Search PubMed
  2. Atrial fibrillation guideline Van Gelder IC, Rienstra M, Bunting KV, et al. 2024 ESC guidelines for the management of atrial fibrillation. Eur Heart J 2024;45(36):3314–3414.
  3. Alcohol and heart rhythm at Oktoberfest Brunner S, Herbel R, Drobesch C, et al. Alcohol consumption, sinus tachycardia, and cardiac arrhythmias at the Munich Octoberfest: results from the Munich Beer Related Electrocardiogram Workup Study (MunichBREW). Eur Heart J 2017;38(27):2100–2106. Search PubMed
  4. Alcohol and arrhythmias in young adults Acute alcohol consumption and arrhythmias in young adults: the MunichBREW II study. 2024. PMID 39363568.
  5. Holiday heart syndrome, revisited Tonelo D, Providência R, Gonçalves L. Holiday heart syndrome revisited after 34 years. Arq Bras Cardiol 2013;101(2):183–189. PMID 24030078.
  6. Atrial fibrillation and stroke Wolf PA, Abbott RD, Kannel WB. Atrial fibrillation as an independent risk factor for stroke: the Framingham Study. Stroke 1991;22(8):983–988. Search PubMed
  7. Heart attacks and the holidays Mohammad et al. 2018; Phillips et al. 2004. See Chapter 4.
Ch. 7Heartburn and a Swollen Toe9
  1. Reflux guideline Katz PO, Dunbar KB, Schnoll-Sussman FH, et al. ACG clinical guideline for the diagnosis and management of gastroesophageal reflux disease. Am J Gastroenterol 2022;117(1):27–56. Search PubMed
  2. Dinner timing and reflux Fujiwara Y, Machida A, Watanabe Y, et al. Association between dinner-to-bed time and gastro-esophageal reflux disease. Am J Gastroenterol 2005;100(12):2633–2636. Search PubMed
  3. Sleeping on the left side Schuitenmaker JM, van Dijk M, Oude Nijhuis RAB, Smout AJPM, Bredenoord AJ. Associations between sleep position and nocturnal gastroesophageal reflux: a study using concurrent monitoring of sleep position and esophageal pH and impedance. Am J Gastroenterol 2022;117(2):346–351. Search PubMed
  4. Gout guideline FitzGerald JD, Dalbeth N, Mikuls T, et al. 2020 American College of Rheumatology guideline for the management of gout. Arthritis Care Res 2020;72(6):744–760.
  5. Amount and type of alcohol and gout flares Neogi T, Chen C, Niu J, et al. Alcohol quantity and type on risk of recurrent gout attacks: an internet-based case-crossover study. Am J Med 2014;127(4):311–318. Search PubMed
  6. Alcohol as a gout trigger Zhang Y, Woods R, Chaisson CE, et al. Alcohol consumption as a trigger of recurrent gout attacks. Am J Med 2006;119(9):800.e13–800.e18. Search PubMed
  7. Purine-rich foods and gout flares Zhang Y, Chen C, Choi H, et al. Purine-rich foods intake and recurrent gout attacks. Ann Rheum Dis 2012;71(9):1448–1453. Search PubMed
  8. Gout flares at night Choi HK, Niu J, Neogi T, et al. Nocturnal risk of gout attacks. Arthritis Rheumatol 2015;67(2):555–562. Search PubMed
  9. Temperature and urate crystals Loeb JN. The influence of temperature on the solubility of monosodium urate. Arthritis Rheum 1972;15(2):189–192. Search PubMed
Ch. 8What the Scale Is Actually Telling You6
  1. Winter Weight Watch trial Mason F, Farley A, Pallan M, Sitch A, Easter C, Daley AJ. Effectiveness of a brief behavioural intervention to prevent weight gain over the Christmas holiday period: randomised controlled trial. BMJ 2018;363:k4867. Search PubMed
  2. Preventing holiday weight gain: systematic review Interventions for the prevention of weight gain during festive and holiday periods in children and adults: a systematic review. PMCID PMC11611437.
  3. Glycogen and water Kreitzman SN, Coxon AY, Szaz KF. Glycogen storage: illusions of easy weight loss, excessive weight regain, and distortions in estimates of body composition. Am J Clin Nutr 1992;56(1 Suppl):292S–293S. Search PubMed
  4. Energy in body fat Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet 2011;378(9793):826–837. Search PubMed
  5. Holiday weight that stays Yanovski et al. 2000. See Chapter 4.
  6. Short fasts and fat loss Klein and Kiat 2015. See Chapter 1.
Ch. 9Your Body Clock Is in the Wrong Time Zone7
  1. Alcohol and sleep: systematic review Gardiner C, Weakley J, Burke LM, et al. The effect of alcohol on subsequent sleep in healthy adults: a systematic review and meta-analysis. Sleep Med Rev 2025;80:102030. Search PubMed
  2. Alcohol and normal sleep Ebrahim IO, Shapiro CM, Williams AJ, Fenwick PB. Alcohol and sleep I: effects on normal sleep. Alcohol Clin Exp Res 2013;37(4):539–549. Search PubMed
  3. Light and circadian rhythm disorders Auger RR, Burgess HJ, Emens JS, et al. Clinical practice guideline for the treatment of intrinsic circadian rhythm sleep-wake disorders. J Clin Sleep Med 2015;11(10):1199–1236. Search PubMed
  4. Social jet lag Wittmann M, Dinich J, Merrow M, Roenneberg T. Social jetlag: misalignment of biological and social time. Chronobiol Int 2006;23(1–2):497–509. Search PubMed
  5. Social jet lag and weight Roenneberg T, Allebrandt KV, Merrow M, Vetter C. Social jetlag and obesity. Curr Biol 2012;22(10):939–943. Search PubMed
  6. The body clock runs a little over 24 hours Czeisler CA, Duffy JF, Shanahan TL, et al. Stability, precision, and near-24-hour period of the human circadian pacemaker. Science 1999;284(5423):2177–2181. Search PubMed
  7. Jet lag Sack RL. Jet lag. N Engl J Med 2010;362(5):440–447.
Ch. 10A Dry January, or Just a Drier One?5
  1. A month off alcohol and health markers Mehta G, Macdonald S, Cronberg A, et al. Short-term abstinence from alcohol and changes in cardiovascular risk factors, liver function tests and cancer-related growth factors: a prospective observational study. BMJ Open 2018;8(5):e020673. Search PubMed
  2. Dry January and drinking six months later de Visser RO, Robinson E, Bond R. Voluntary temporary abstinence from alcohol during "Dry January" and subsequent alcohol use. Health Psychol 2016;35(3):281–289. Search PubMed
  3. Alcohol-related liver disease guideline European Association for the Study of the Liver. EASL clinical practice guidelines: management of alcohol-related liver disease. J Hepatol 2018;69(1):154–181.
  4. Alcohol withdrawal guideline American Society of Addiction Medicine. The ASAM clinical practice guideline on alcohol withdrawal management. J Addict Med 2020;14(3S Suppl 1):1–72.
  5. Standard drinks in different countries National Institute on Alcohol Abuse and Alcoholism (US); National Health and Medical Research Council (Australia); National Health Service (UK).
Ch. 11A Glass a Day?12
  1. Alcohol as a carcinogen IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Personal habits and indoor combustions. IARC Monographs vol. 100E. Lyon: IARC; 2012.
  2. Alcohol and cancer advisory Office of the US Surgeon General. Alcohol and cancer risk: the U.S. Surgeon General's Advisory. US Department of Health and Human Services; 2025.
  3. Breast cancer at low intake Bagnardi V, Rota M, Botteri E, et al. Alcohol consumption and site-specific cancer risk: a comprehensive dose–response meta-analysis. Br J Cancer 2015;112(3):580–593. Search PubMed
  4. The sick-quitter problem Shaper AG, Wannamethee G, Walker M. Alcohol and mortality in British men: explaining the U-shaped curve. Lancet 1988;2(8623):1267–1273. Search PubMed
  5. Low-volume drinking and mortality Zhao J, Stockwell T, Naimi T, et al. Association between daily alcohol intake and risk of all-cause mortality: a systematic review and meta-analyses. JAMA Netw Open 2023;6(3):e236185. Search PubMed
  6. Lifestyle and genetic evidence in UK Biobank Biddinger KJ, Emdin CA, Haas ME, et al. Association of habitual alcohol intake with risk of cardiovascular disease. JAMA Netw Open 2022;5(3):e223849. Search PubMed
  7. Genes, alcohol and stroke in China Millwood IY, Walters RG, Mei XW, et al. Conventional and genetic evidence on alcohol and vascular disease aetiology: a prospective study of 500 000 men and women in China. Lancet 2019;393(10183):1831–1842. Search PubMed
  8. Resveratrol and mortality Semba RD, Ferrucci L, Bartali B, et al. Resveratrol levels and all-cause mortality in older community-dwelling adults. JAMA Intern Med 2014;174(7):1077–1084. Search PubMed
  9. Flushing and esophageal cancer Brooks PJ, Enoch MA, Goldman D, Li TK, Yokoyama A. The alcohol flushing response: an unrecognized risk factor for esophageal cancer from alcohol consumption. PLoS Med 2009;6(3):e50. Search PubMed
  10. No safe level of drinking Anderson BO, Berdzuli N, Ilbawi A, et al. Health and cancer risks associated with low levels of alcohol consumption. Lancet Public Health 2023;8(1):e6–e7. Search PubMed
  11. Canada's guidance Paradis C, Butt P, Shield K, et al. Canada's guidance on alcohol and health: final report. Ottawa: Canadian Centre on Substance Use and Addiction; 2023.
  12. Cancer warning labels in Ireland Public Health (Alcohol) (Labelling) Regulations 2023. Government of Ireland; 2023.
Ch. 12The Restrict-and-Rebound Loop3
  1. The milkshake experiment Herman CP, Mack D. Restrained and unrestrained eating. J Pers 1975;43(4):647–660. Search PubMed
  2. Dieting and rebound eating Polivy J, Herman CP. Dieting and binging: a causal analysis. Am Psychol 1985;40(2):193–201. Search PubMed
  3. Flexible and rigid control Westenhoefer J, Stunkard AJ, Pudel V. Validation of the flexible and rigid control dimensions of dietary restraint. Int J Eat Disord 1999;26(1):53–64. Search PubMed
Ch. 13The Power of January First7
  1. The fresh start effect Dai H, Milkman KL, Riis J. The fresh start effect: temporal landmarks motivate aspirational behavior. Manage Sci 2014;60(10):2563–2582. Search PubMed
  2. Approach and avoidance goals Oscarsson M, Carlbring P, Andersson G, Rozental A. A large-scale experiment on New Year's resolutions: approach-oriented goals are more successful than avoidance-oriented goals. PLoS One 2020;15(12):e0234097. Search PubMed
  3. If… then… plans Gollwitzer PM, Sheeran P. Implementation intentions and goal achievement: a meta-analysis of effects and processes. Adv Exp Soc Psychol 2006;38:69–119. Search PubMed
  4. How long habits take Lally P, van Jaarsveld CHM, Potts HWW, Wardle J. How are habits formed: modelling habit formation in the real world. Eur J Soc Psychol 2010;40(6):998–1009. Search PubMed
  5. How long habits take: systematic review Singh B, Murphy A, Maher C, Smith AE. Time to form a habit: a systematic review and meta-analysis of health behaviour habit formation and its determinants. Healthcare (Basel) 2024;12(23):2488. Search PubMed
  6. New Year's resolutions six months on Norcross JC, Mrykalo MS, Blagys MD. Auld lang syne: success predictors, change processes, and self-reported outcomes of New Year's resolvers and nonresolvers. J Clin Psychol 2002;58(4):397–405. Search PubMed
  7. Where "21 days" came from Maltz M. Psycho-Cybernetics. Englewood Cliffs, NJ: Prentice-Hall; 1960.
Ch. 14An Ordinary January3
  1. Weighing yourself over the holidays Mason et al. 2018. See Chapter 8.
  2. If… then… plans Gollwitzer and Sheeran 2006. See Chapter 13.
  3. When to call in a professional Gathered from the sources for Chapters 5 to 10.
BackWorksheets at the back of the book6
  1. When to call emergency services See Chapters 5, 6, 7 and 10 (NIAAA; ESC 2024; ASAM 2020; Katz et al. 2022; FitzGerald et al. 2020).
  2. Morning-after inventory See Chapters 1 and 4.
  3. Drinks and sleep diary See Chapters 5 and 9 (Gardiner et al. 2025).
  4. Alcohol-free days calendar See Chapter 10 (de Visser et al. 2016).
  5. January goal sheet See Chapter 13 (Gollwitzer and Sheeran 2006; Oscarsson et al. 2020; Lally et al. 2010).
  6. An ordinary January and next holiday season See Chapter 14 (Mason et al. 2018).
Cover of Do I Need to Quit Drinking?

Vol. 16

Do I Need to Quit Drinking?

Evidence last reviewed October 23, 2026

Ch. 1Do I Need to Quit Drinking?4
  1. Most excessive drinkers are not dependent Esser MB, Hedden SL, Kanny D, et al. Prevalence of alcohol dependence among US adult drinkers, 2009–2011. Prev Chronic Dis 2014;11:E206. doi:10.5888/pcd11.140329. PMID 25412029.
  2. Alcohol as a Group 1 carcinogen IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Personal habits and indoor combustions. IARC Monogr Eval Carcinog Risks Hum 2012;100E:1–538.
  3. Alcohol and cancer risk Office of the US Surgeon General. Alcohol and Cancer Risk: The U.S. Surgeon General's Advisory. Washington, DC: US Department of Health and Human Services; 2025.
  4. Withdrawal when someone dependent stops suddenly American Society of Addiction Medicine. The ASAM clinical practice guideline on alcohol withdrawal management. J Addict Med 2020;14(3S Suppl 1):1–72. doi:10.1097/ADM.0000000000000668. PMID 32511109.
Ch. 2The 6 p.m. Drink7
  1. Alcohol and dopamine in the human brain Boileau I, Assaad JM, Pihl RO, et al. Alcohol promotes dopamine release in the human nucleus accumbens. Synapse 2003;49(4):226–231. doi:10.1002/syn.10226. PMID 12827641.
  2. Wanting and liking Berridge KC, Robinson TE. Liking, wanting, and the incentive-sensitization theory of addiction. Am Psychol 2016;71(8):670–679. Search PubMed
  3. Brake, accelerator, tolerance and rebound ASAM 2020. See Chapter 1.
  4. From goals to habits Everitt BJ, Robbins TW. Drug addiction: updating actions to habits to compulsions ten years on. Annu Rev Psychol 2016;67:23–50. Search PubMed
  5. Does willpower run out? Hagger MS, Chatzisarantis NLD, Alberts H, et al. A multilab preregistered replication of the ego-depletion effect. Perspect Psychol Sci 2016;11(4):546–573. Search PubMed
  6. Four reasons for drinking Cooper ML. Motivations for alcohol use among adolescents: development and validation of a four-factor model. Psychol Assess 1994;6(2):117–128. Search PubMed
  7. Why people drink, and what follows Bresin K, Mekawi Y. The "why" of drinking matters: a meta-analysis of the association between drinking motives and drinking outcomes. Alcohol Clin Exp Res 2021;45(1):38–50. doi:10.1111/acer.14518. PMID 33206387.
Ch. 3What Alcohol Takes6
  1. Alcohol and sleep Ebrahim IO, Shapiro CM, Williams AJ, Fenwick PB. Alcohol and sleep I: effects on normal sleep. Alcohol Clin Exp Res 2013;37(4):539–549. doi:10.1111/acer.12006. PMID 23347102.
  2. Cutting down and blood pressure Roerecke M, Kaczorowski J, Tobe SW, et al. The effect of a reduction in alcohol consumption on blood pressure: a systematic review and meta-analysis. Lancet Public Health 2017;2(2):e108–e120. doi:10.1016/S2468-2667(17)30003-830003-8). PMID 29253389.
  3. Abstinence and atrial fibrillation Voskoboinik A, Kalman JM, De Silva A, et al. Alcohol abstinence in drinkers with atrial fibrillation. N Engl J Med 2020;382(1):20–28. doi:10.1056/NEJMoa1817591. PMID 31893513.
  4. "Holiday heart." Ettinger PO, Wu CF, De La Cruz C Jr, et al. Arrhythmias and the "holiday heart": alcohol-associated cardiac rhythm disorders. Am Heart J 1978;95(5):555–562. Search PubMed
  5. Alcohol and depression Boden JM, Fergusson DM. Alcohol and depression. Addiction 2011;106(5):906–914. doi:10.1111/j.1360-0443.2010.03351.x. PMID 21382111.
  6. Blood pressure thresholds Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults. Hypertension 2018;71(6):e13–e115.
Ch. 4Not Every Body Drinks the Same6
  1. Women and alcohol National Institute on Alcohol Abuse and Alcoholism (NIAAA). Women and Alcohol. Fact sheet; updated 2025.
  2. Older adults and alcohol NIAAA. Aging and Alcohol. Updated 2025.
  3. Alcohol and medicines in older adults Holton AE, Keeney C, Ryan B, et al. Prevalence of potentially serious alcohol-medication interactions in older adults in a community pharmacy setting. BMJ Open 2020;10(8):e035212. doi:10.1136/bmjopen-2019-035212. PMID 32868351.
  4. Genes and alcohol use disorder Verhulst B, Neale MC, Kendler KS. The heritability of alcohol use disorders: a meta-analysis of twin and adoption studies. Psychol Med 2015;45(5):1061–1072. doi:10.1017/S0033291714002165. PMID 25171596.
  5. Alcohol in pregnancy Centers for Disease Control and Prevention (CDC). About Alcohol Use During Pregnancy. Atlanta, GA: CDC; 2024.
  6. ALDH2 and flushing See Volume 15 of this series, Chapter 11.
Ch. 5Ten Questions in Two Minutes7
  1. The AUDIT, its zones and the reproduced questionnaire Babor TF, Higgins-Biddle JC, Saunders JB, Monteiro MG. AUDIT: The Alcohol Use Disorders Identification Test. Guidelines for Use in Primary Care. 2nd ed. Geneva: World Health Organization; 2001 (WHO/MSD/MSB/01.6a). Reproduced and translated with permission.
  2. How the AUDIT was developed Saunders JB, Aasland OG, Babor TF, de la Fuente JR, Grant M. Development of the Alcohol Use Disorders Identification Test (AUDIT): WHO collaborative project on early detection of persons with harmful alcohol consumption, II. Addiction 1993;88(6):791–804. doi:10.1111/j.1360-0443.1993.tb02093.x. PMID 8329970.
  3. The AUDIT, reviewed Reinert DF, Allen JP. The Alcohol Use Disorders Identification Test: an update of research findings. Alcohol Clin Exp Res 2007;31(2):185–199. doi:10.1111/j.1530-0277.2006.00295.x. PMID 17250609.
  4. The three-question AUDIT-C Bradley KA, DeBenedetti AF, Volk RJ, et al. AUDIT-C as a brief screen for alcohol misuse in primary care. Alcohol Clin Exp Res 2007;31(7):1208–1217. doi:10.1111/j.1530-0277.2007.00403.x. PMID 17451397.
  5. Screening recommendation US Preventive Services Task Force; Curry SJ, Krist AH, Owens DK, et al. Screening and behavioral counseling interventions to reduce unhealthy alcohol use in adolescents and adults: US Preventive Services Task Force recommendation statement. JAMA 2018;320(18):1899–1909. Search PubMed
  6. Standard drinks in 37 countries Kalinowski A, Humphreys K. Governmental standard drink definitions and low-risk alcohol consumption guidelines in 37 countries. Addiction 2016;111(7):1293–1298. doi:10.1111/add.13341. PMID 27073140.
  7. Self-monitoring and digital programmes Kaner EF, Beyer FR, Garnett C, et al. Personalised digital interventions for reducing hazardous and harmful alcohol consumption in community-dwelling populations. Cochrane Database Syst Rev 2017;9:CD011479. doi:10.1002/14651858.CD011479.pub2. PMID 28944453.
Ch. 6"Alcoholic" Isn't a Switch4
  1. Recovery from alcohol dependence Dawson DA, Grant BF, Stinson FS, et al. Recovery from DSM-IV alcohol dependence: United States, 2001–2002. Addiction 2005;100(3):281–292. doi:10.1111/j.1360-0443.2004.00964.x. PMID 15733237.
  2. Brief interventions in primary care Kaner EF, Beyer FR, Muirhead C, et al. Effectiveness of brief alcohol interventions in primary care populations. Cochrane Database Syst Rev 2018;2:CD004148. doi:10.1002/14651858.CD004148.pub4. PMID 29476653.
  3. Stigma and seeking help Hammarlund R, Crapanzano KA, Luce L, et al. Review of the effects of self-stigma and perceived social stigma on the treatment-seeking decisions of individuals with drug- and alcohol-use disorders. Subst Abuse Rehabil 2018;9:115–136. doi:10.2147/SAR.S183256. PMID 30538599.
  4. Alcohol use disorder as a spectrum American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th ed. Arlington, VA: APA; 2013.
Ch. 7Three Roads6
  1. Every notch counts Witkiewitz K, Hallgren KA, Kranzler HR, et al. Clinical validation of reduced alcohol consumption after treatment for alcohol dependence using the World Health Organization risk drinking levels. Alcohol Clin Exp Res 2017;41(1):179–186. doi:10.1111/acer.13272. PMID 28019652.
  2. Risk levels as a trial outcome Witkiewitz K, Anton RF, O'Malley SS, et al. Reductions in World Health Organization risk drinking levels as a primary efficacy end point for alcohol clinical trials: a review. JAMA Psychiatry 2025;82(12):1246–1254. doi:10.1001/jamapsychiatry.2025.2508. PMID 40960803.
  3. WHO risk drinking levels World Health Organization. International Guide for Monitoring Alcohol Consumption and Related Harm. Geneva: WHO; 2000.
  4. Which recovery lasts Dawson DA, Goldstein RB, Grant BF. Rates and correlates of relapse among individuals in remission from DSM-IV alcohol dependence: a 3-year follow-up. Alcohol Clin Exp Res 2007;31(12):2036–2045. doi:10.1111/j.1530-0277.2007.00536.x. PMID 18034696.
  5. Pregnancy CDC 2024. See Chapter 4.
  6. Liver disease European Association for the Study of the Liver. EASL clinical practice guidelines: management of alcohol-related liver disease. J Hepatol 2018;69(1):154–181. doi:10.1016/j.jhep.2018.03.018.
Ch. 8When Quitting Needs a Doctor5
  1. Withdrawal, its timeline and its management ASAM 2020. See Chapter 1.
  2. The guideline in brief Lindsay DL, Freedman K, Jarvis M, et al. Executive summary of the American Society of Addiction Medicine (ASAM) clinical practice guideline on alcohol withdrawal management. J Addict Med 2020;14(5):376–392. doi:10.1097/ADM.0000000000000732.
  3. Kindling Becker HC. Kindling in alcohol withdrawal. Alcohol Health Res World 1998;22(1):25–33. PMID 15706729.
  4. Thiamine National Institute for Health and Care Excellence (NICE). Alcohol-Use Disorders: Diagnosis and Management of Physical Complications (CG100). London: NICE; 2010, updated 2017.
  5. Helpline Substance Abuse and Mental Health Services Administration (SAMHSA). National Helpline. Rockville, MD: SAMHSA; 2026.
Ch. 9The Forgotten Medicine Cabinet9
  1. How few people are offered medicine Han B, Jones CM, Einstein EB, Powell PA, Compton WM. Use of medications for alcohol use disorder in the US: results from the 2019 National Survey on Drug Use and Health. JAMA Psychiatry 2021;78(8). doi:10.1001/jamapsychiatry.2021.1271. PMID 34132744.
  2. Medicines for alcohol use disorder: the 2023 review McPheeters M, O'Connor EA, Riley S, et al. Pharmacotherapy for alcohol use disorder: a systematic review and meta-analysis. JAMA 2023;330(17):1653–1665. doi:10.1001/jama.2023.19761. PMID 37934220.
  3. Medicines for alcohol use disorder: the 2014 review Jonas DE, Amick HR, Feltner C, et al. Pharmacotherapy for adults with alcohol use disorders in outpatient settings: a systematic review and meta-analysis. JAMA 2014;311(18):1889–1900. doi:10.1001/jama.2014.3628. PMID 24825644.
  4. Gabapentin Kranzler HR, Feinn R, Morris P, Hartwell EE. A meta-analysis of the efficacy of gabapentin for treating alcohol use disorder. Addiction 2019;114(9):1547–1555. doi:10.1111/add.14655. PMID 31077485.
  5. Disulfiram Skinner MD, Lahmek P, Pham H, Aubin HJ. Disulfiram efficacy in the treatment of alcohol dependence: a meta-analysis. PLoS One 2014;9(2):e87366. doi:10.1371/journal.pone.0087366. PMID 24520330.
  6. Nalmefene Palpacuer C, Laviolle B, Boussageon R, et al. Risks and benefits of nalmefene in the treatment of adult alcohol dependence: a systematic literature review and meta-analysis of published and unpublished double-blind randomized controlled trials. PLoS Med 2015;12(12):e1001924. doi:10.1371/journal.pmed.1001924. PMID 26694529.
  7. Baclofen Bschor T, Henssler J, Müller M, Baethge C. Baclofen for alcohol use disorder: a systematic meta-analysis. Acta Psychiatr Scand 2018;138(3):232–242. doi:10.1111/acps.12905. PMID 29888478.
  8. Semaglutide Hendershot CS, Bremmer MP, Paladino MB, et al. Once-weekly semaglutide in adults with alcohol use disorder: a randomized clinical trial. JAMA Psychiatry 2025;82(4):395–405. doi:10.1001/jamapsychiatry.2024.4789. PMID 39937469.
  9. Interactions and cautions Prescribing information for each medicine (US Food and Drug Administration; European Medicines Agency).
Ch. 10You Don't Have to Do It Alone6
  1. AA and 12-step programmes Kelly JF, Humphreys K, Ferri M. Alcoholics Anonymous and other 12-step programs for alcohol use disorder. Cochrane Database Syst Rev 2020;3:CD012880. doi:10.1002/14651858.CD012880.pub2. PMID 32159228.
  2. Cognitive behavioural therapy Magill M, Ray L, Kiluk B, et al. A meta-analysis of cognitive-behavioral therapy for alcohol or other drug use disorders: treatment efficacy by contrast condition. J Consult Clin Psychol 2019;87(12):1093–1105. doi:10.1037/ccp0000447. PMID 31599606.
  3. Motivational interviewing Miller WR, Rollnick S. Motivational Interviewing: Helping People Change. 3rd ed. New York: Guilford Press; 2013.
  4. Digital programmes Kaner et al. 2017. See Chapter 5.
  5. CRAFT for families Roozen HG, de Waart R, van der Kroft P. Community reinforcement and family training: an effective option to engage treatment-resistant substance-abusing individuals in treatment. Addiction 2010;105(10):1729–1738. doi:10.1111/j.1360-0443.2010.03016.x. PMID 20626372.
  6. SMART Recovery Beck AK, Forbes E, Baker AL, et al. Systematic review of SMART Recovery: outcomes, process variables, and implications for research. Psychol Addict Behav 2017;31(1):1–20. doi:10.1037/adb0000237. PMID 28165272.
Ch. 11Thirty Days6
  1. A month without alcohol Mehta G, Macdonald S, Cronberg A, et al. Short-term abstinence from alcohol and changes in cardiovascular risk factors, liver function tests and cancer-related growth factors: a prospective observational study. BMJ Open 2018;8(5):e020673. PMID 29730627.
  2. Sleep after stopping Chakravorty S, Chaudhary NS, Brower KJ. Alcohol dependence and its relationship with insomnia and other sleep disorders. Alcohol Clin Exp Res 2016;40(11):2271–2282. doi:10.1111/acer.13217. PMID 27706838.
  3. Urge surfing Bowen S, Marlatt A. Surfing the urge: brief mindfulness-based intervention for college student smokers. Psychol Addict Behav 2009;23(4):666–671. doi:10.1037/a0017127. PMID 20025372.
  4. If-then plans Cooke R, McEwan H, Norman P. The effect of forming implementation intentions on alcohol consumption: a systematic review and meta-analysis. Drug Alcohol Rev 2023;42(1):68–80. doi:10.1111/dar.13553. PMID 36173203.
  5. Dry January and what follows de Visser RO, Robinson E, Bond R. Voluntary temporary abstinence from alcohol during "Dry January" and subsequent alcohol use. Health Psychol 2016;35(3):281–289. Search PubMed
  6. Dry January outside supported programmes de Visser RO, Piper R. Short- and longer-term benefits of temporary alcohol abstinence during "Dry January" are not also observed among adult drinkers in the general population: prospective cohort study. Alcohol Alcohol 2020;55(4):433–438. doi:10.1093/alcalc/agaa025. PMID 32391879.
Ch. 12The People Holding Out a Glass3
  1. Misjudging how much others drink Foxcroft DR, Moreira MT, Almeida Santimano NM, Smith LA. Social norms information for alcohol misuse in university and college students. Cochrane Database Syst Rev 2015;(12):CD006748. doi:10.1002/14651858.CD006748.pub4. PMID 26711838.
  2. Alcohol-free and low-alcohol drinks Kersbergen I, Oldham M, Brown J, et al. The use of alcohol-free and low alcohol drinks in attempts to restrict alcohol consumption: findings from a cross-sectional survey. Int J Drug Policy 2025;145:105030. doi:10.1016/j.drugpo.2025.105030. PMID 41077015.
  3. Partners and heavy drinking Bartel SJ, Sherry SB, Molnar DS, et al. Do romantic partners influence each other's heavy episodic drinking? Support for the partner influence hypothesis in a three-year longitudinal study. Addict Behav 2017;69:55–58. doi:10.1016/j.addbeh.2017.01.020. PMID 28131933.
Ch. 13Day 314
  1. The pre-mortem Klein G. Performing a project premortem. Harv Bus Rev 2007;85(9):18–19. Search PubMed
  2. Relapse prevention Irvin JE, Bowers CA, Dunn ME, Wang MC. Efficacy of relapse prevention: a meta-analytic review. J Consult Clin Psychol 1999;67(4):563–570. doi:10.1037/0022-006X.67.4.563. PMID 10450627.
  3. The abstinence violation effect Marlatt GA, Gordon JR, eds. Relapse Prevention: Maintenance Strategies in the Treatment of Addictive Behaviors. New York: Guilford Press; 1985.
  4. Which recovery lasts Dawson et al. 2007. See Chapter 7.
Ch. 14A Year From Now3
  1. The brain in recovery Rosenbloom MJ, Pfefferbaum A. Magnetic resonance imaging of the living brain: evidence for brain degeneration among alcoholics and recovery with abstinence. Alcohol Res Health 2008;31(4):362–376. PMID 23584010.
  2. White matter recovery and relapse Pfefferbaum A, Rosenbloom MJ, Chu W, et al. White matter microstructural recovery with abstinence and decline with relapse in alcohol dependence interacts with normal ageing: a controlled longitudinal DTI study. Lancet Psychiatry 2014;1(3):202–212. doi:10.1016/S2215-0366(14)70301-370301-3). PMID 26360732.
  3. Memory and balance Rosenbloom MJ, Rohlfing T, O'Reilly AW, et al. Improvement in memory and static balance with abstinence in alcoholic men and women: selective relations with change in brain structure. Psychiatry Res 2007;155(2):91–102. PMID 17407808.
BackWorksheets at the back of the book7
  1. When to call emergency services See Chapters 1, 3, 4, 8, 9 and 10 (ASAM 2020; NIAAA).
  2. Where to find help See Chapters 3, 8 and 10 (988 Suicide and Crisis Lifeline; SAMHSA National Helpline).
  3. Three safety questions and the card for the doctor See Chapters 1 and 8 (ASAM 2020).
  4. AUDIT score sheet See Chapter 5 (Babor et al. 2001).
  5. Drink diary, invoice and before-and-after sheet See Chapters 3, 5 and 11.
  6. Three-Road Map See Chapter 7 (Witkiewitz et al. 2017; Dawson et al. 2007).
  7. My 30 days, comebacks, day 31 and slip plan See Chapters 11, 12 and 13 (Cooke et al. 2023; Irvin et al. 1999).
Cover of Why Do I Always Quit by February?

Vol. 17

Why Do I Always Quit by February?

Evidence last reviewed October 28, 2026 · review draft

Ch. 1Why Do I Always Quit by February?5
  1. How many people make resolutions, and which ones YouGov. Americans' New Year's resolutions for 2026. Survey of 1,104 US adults, December 9–11, 2025.
  2. "Quitter's Day." Strava. Annual analysis of logged activities in January, 2019 and 2020 releases.
  3. Resolvers and non-resolvers after six months Norcross JC, Mrykalo MS, Blagys MD. Auld lang syne: success predictors, change processes, and self-reported outcomes of New Year's resolvers and nonresolvers. J Clin Psychol 2002;58(4):397–405.
  4. Slips among successful resolvers over two years Norcross JC, Vangarelli DJ. The resolution solution: longitudinal examination of New Year's change attempts. J Subst Abuse 1988;1(2):127–134.
  5. A large trial of New Year's resolutions Oscarsson M, Carlbring P, Andersson G, Rozental A. A large-scale experiment on New Year's resolutions: approach-oriented goals are more successful than avoidance-oriented goals. PLoS One 2020;15(12):e0234097. doi:10.1371/journal.pone.0234097.
Ch. 2The Contract You Signed on January 14
  1. The hot-cold empathy gap Loewenstein G. Hot-cold empathy gaps and medical decision making. Health Psychol 2005;24(4 Suppl):S49–S56.
  2. The planning fallacy Buehler R, Griffin D, Ross M. Exploring the "planning fallacy": why people underestimate their task completion times. J Pers Soc Psychol 1994;67(3):366–381.
  3. False hope syndrome Polivy J, Herman CP. The false-hope syndrome: unfulfilled expectations of self-change. Curr Dir Psychol Sci 2000;9(4):128–131. doi:10.1111/1467-8721.00076.
  4. The fresh start effect Dai H, Milkman KL, Riis J. The fresh start effect: temporal landmarks motivate aspirational behavior. Manage Sci 2014;60(10):2563–2582. doi:10.1287/mnsc.2014.1901.
Ch. 3Willpower Isn't a Fuel Tank5
  1. The original radish-and-cookie study Baumeister RF, Bratslavsky E, Muraven M, Tice DM. Ego depletion: is the active self a limited resource? J Pers Soc Psychol 1998;74(5):1252–1265.
  2. The first multi-lab replication Hagger MS, Chatzisarantis NLD, Alberts H, et al. A multilab preregistered replication of the ego-depletion effect. Perspect Psychol Sci 2016;11(4):546–573. doi:10.1177/1745691616652873.
  3. The second multi-site test Vohs KD, Schmeichel BJ, Lohmann S, et al. A multisite preregistered paradigmatic test of the ego-depletion effect. Psychol Sci 2021;32(10):1566–1581. doi:10.1177/0956797621989733.
  4. Everyday temptations and self-control Hofmann W, Baumeister RF, Förster G, Vohs KD. Everyday temptations: an experience sampling study of desire, conflict, and self-control. J Pers Soc Psychol 2012;102(6):1318–1335. doi:10.1037/a0026545.
  5. Habits and self-control Galla BM, Duckworth AL. More than resisting temptation: beneficial habits mediate the relationship between self-control and positive life outcomes. J Pers Soc Psychol 2015;109(3):508–525.
Ch. 4Twenty-One Days, or Two Hundred?4
  1. Where 21 days came from Maltz M. Psycho-Cybernetics. 1960. Traced by the Health Behaviour Research Centre, University College London, 2012.
  2. How long habits take to form Singh B, Murphy A, Maher C, Smith AE. Time to form a habit: a systematic review and meta-analysis of health behaviour habit formation and its determinants. Healthcare (Basel) 2024;12(23):2488. doi:10.3390/healthcare12232488.
  3. Modelling habit formation in everyday life Lally P, van Jaarsveld CHM, Potts HWW, Wardle J. How are habits formed: modelling habit formation in the real world. Eur J Soc Psychol 2010;40(6):998–1009.
  4. Exercise habits in new gym members Kaushal N, Rhodes RE. Exercise habit formation in new gym members: a longitudinal study. J Behav Med 2015;38(4):652–663. doi:10.1007/s10865-015-9640-7.
Ch. 5Your Body on February 154
  1. Short sleep, hunger hormones and appetite Spiegel K, Tasali E, Penev P, Van Cauter E. Brief communication: sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite. Ann Intern Med 2004;141(11):846–850.
  2. Partial sleep loss and energy intake Al Khatib HK, Harding SV, Darzi J, Pot GK. The effects of partial sleep deprivation on energy balance: a systematic review and meta-analysis. Eur J Clin Nutr 2017;71(5):614–624. doi:10.1038/ejcn.2016.201.
  3. Sleeping more and free sugars Al Khatib HK, Hall WL, Creedon A, et al. Sleep extension is a feasible lifestyle intervention in free-living adults who are habitually short sleepers: a potential strategy for decreasing intake of free sugars? A randomized controlled pilot study. Am J Clin Nutr 2018;107(1):43–53. doi:10.1093/ajcn/nqx030.
  4. Stress and habits Schwabe L, Wolf OT. Stress prompts habit behavior in humans. J Neurosci 2009;29(22):7191–7198. doi:10.1523/JNEUROSCI.0979-09.2009.
Ch. 6The Gym Card and the Too-Hard First Week5
  1. Gym memberships and attendance DellaVigna S, Malmendier U. Paying not to go to the gym. Am Econ Rev 2006;96(3):694–719.
  2. Exercise intensity and pleasure Ekkekakis P, Parfitt G, Petruzzello SJ. The pleasure and displeasure people feel when they exercise at different intensities: decennial update and progress towards a tripartite rationale for exercise intensity prescription. Sports Med 2011;41(8):641–671.
  3. How exercise feels and future activity Rhodes RE, Kates A. Can the affective response to exercise predict future motives and physical activity behavior? A systematic review of published evidence. Ann Behav Med 2015;49(5):715–731. doi:10.1007/s12160-015-9704-5.
  4. The 10% rule Buist I, Bredeweg SW, van Mechelen W, Lemmink KAPM, Pepping GJ, Diercks RL. No effect of a graded training program on the number of running-related injuries in novice runners: a randomized controlled trial. Am J Sports Med 2008;36(1):33–39. doi:10.1177/0363546507307505.
  5. Screening before exercise Riebe D, Franklin BA, Thompson PD, et al. Updating ACSM's recommendations for exercise preparticipation health screening. Med Sci Sports Exerc 2015;47(11):2473–2479. doi:10.1249/MSS.0000000000000664.
Ch. 7"Clean Eating Starts Monday"5
  1. Named diets compared Johnston BC, Kanters S, Bandayrel K, et al. Comparison of weight loss among named diet programs in overweight and obese adults: a meta-analysis. JAMA 2014;312(9):923–933. doi:10.1001/jama.2014.10397.
  2. Four diets and adherence Dansinger ML, Gleason JA, Griffith JL, Selker HP, Schaefer EJ. Comparison of the Atkins, Ornish, Weight Watchers, and Zone diets for weight loss and heart disease risk reduction: a randomized trial. JAMA 2005;293(1):43–53.
  3. Self-weighing Madigan CM, Daley AJ, Lewis AL, Aveyard P, Jolly K. Is self-weighing an effective tool for weight loss: a systematic literature review and meta-analysis. Int J Behav Nutr Phys Act 2015;12:104. doi:10.1186/s12966-015-0267-4.
  4. Dieting and rebound eating Polivy J, Herman CP. Dieting and binging: a causal analysis. Am Psychol 1985;40(2):193–201.
  5. Flexible and rigid control Westenhoefer J, Stunkard AJ, Pudel V. Validation of the flexible and rigid control dimensions of dietary restraint. Int J Eat Disord 1999;26(1):53–64.
Ch. 8The "Quit" Goals: Alcohol, Sugar, Your Phone7
  1. Approach and avoidance goals Oscarsson et al. 2020. See Chapter 1.
  2. The white bear Wegner DM, Schneider DJ, Carter SR, White TL. Paradoxical effects of thought suppression. J Pers Soc Psychol 1987;53(1):5–13.
  3. Suppressing thoughts of chocolate Erskine JAK. Resistance can be futile: investigating behavioural rebound. Appetite 2008;50(2–3):415–421. doi:10.1016/j.appet.2007.09.006.
  4. The psychology of habit Wood W, Rünger D. Psychology of habit. Annu Rev Psychol 2016;67:289–314.
  5. Dopamine fasting Grinspoon P. Dopamine fasting: misunderstanding science spawns a maladaptive fad. Harvard Health Blog, Harvard Health Publishing, February 26, 2020.
  6. Limiting social media Hunt MG, Marx R, Lipson C, Young J. No more FOMO: limiting social media decreases loneliness and depression. J Soc Clin Psychol 2018;37(10):751–768. doi:10.1521/jscp.2018.37.10.751.
  7. Stopping alcohol safely American Society of Addiction Medicine. The ASAM clinical practice guideline on alcohol withdrawal management. J Addict Med 2020;14(3S Suppl 1):1–72. doi:10.1097/ADM.0000000000000668.
Ch. 9Sleep: The Goal Under Every Other Goal3
  1. Bedtime procrastination Kroese FM, de Ridder DTD, Evers C, Adriaanse MA. Bedtime procrastination: introducing a new area of procrastination. Front Psychol 2014;5:611. doi:10.3389/fpsyg.2014.00611.
  2. Treating chronic insomnia Edinger JD, Arnedt JT, Bertisch SM, et al. Behavioral and psychological treatments for chronic insomnia disorder in adults: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med 2021;17(2):255–262. doi:10.5664/jcsm.8986.
  3. Sleeping more and free sugars Al Khatib et al. 2018. See Chapter 5.
Ch. 10The Handover Note6
  1. "If… then…" plans Gollwitzer PM, Sheeran P. Implementation intentions and goal achievement: a meta-analysis of effects and processes. Adv Exp Soc Psychol 2006;38:69–119.
  2. Thinking about obstacles (WOOP) Wang G, Wang Y, Gai X. A meta-analysis of the effects of mental contrasting with implementation intentions on goal attainment. Front Psychol 2021;12:565202. doi:10.3389/fpsyg.2021.565202.
  3. Immediate rewards and long-term goals Woolley K, Fishbach A. Immediate rewards predict adherence to long-term goals. Pers Soc Psychol Bull 2017;43(2):151–162.
  4. Enjoyment and New Year's resolutions over a year Woolley K, Giurge LM, Fishbach A. Adherence to personal resolutions across time, culture, and goal domains. Psychol Sci 2025;36(8). doi:10.1177/09567976251350960.
  5. Temptation bundling, the first trial Milkman KL, Minson JA, Volpp KGM. Holding the Hunger Games hostage at the gym: an evaluation of temptation bundling. Manage Sci 2014;60(2):283–299. doi:10.1287/mnsc.2013.1784.
  6. Temptation bundling, the larger trial Kirgios EL, Mandel GH, Park Y, et al. Teaching temptation bundling to boost exercise: a field experiment. Organ Behav Hum Decis Process 2020;161(Suppl):20–35. doi:10.1016/j.obhdp.2020.09.003.
Ch. 11Change the Field, Not the Player4
  1. Habits in everyday life Wood W, Quinn JM, Kashy DA. Habits in everyday life: thought, emotion, and action. J Pers Soc Psychol 2002;83(6):1281–1297.
  2. Moving house and changing habits Verplanken B, Roy D. Empowering interventions to promote sustainable lifestyles: testing the habit discontinuity hypothesis in a field experiment. J Environ Psychol 2016;45:127–134. doi:10.1016/j.jenvp.2015.11.008.
  3. The gym megastudy Milkman KL, Gromet D, Ho H, et al. Megastudies improve the impact of applied behavioural science. Nature 2021;600(7889):478–483. doi:10.1038/s41586-021-04128-4.
  4. Deposit contracts Giné X, Karlan D, Zinman J. Put your money where your butt is: a commitment contract for smoking cessation. Am Econ J Appl Econ 2010;2(4):213–235. doi:10.1257/app.2.4.213.
Ch. 12A Slip in Slow Motion4
  1. The abstinence violation effect Marlatt GA, Gordon JR. Relapse Prevention: Maintenance Strategies in the Treatment of Addictive Behaviors. New York: Guilford Press; 1985. Curry S, Marlatt GA, Gordon JR. Abstinence violation effect: validation of an attributional construct with smoking cessation. J Consult Clin Psychol 1987;55(2):145–149.
  2. Self-compassion after breaking an eating rule Adams CE, Leary MR. Promoting self-compassionate attitudes toward eating among restrictive and guilty eaters. J Soc Clin Psychol 2007;26(10):1120–1144. doi:10.1521/jscp.2007.26.10.1120.
  3. Self-compassion and self-improvement Breines JG, Chen S. Self-compassion increases self-improvement motivation. Pers Soc Psychol Bull 2012;38(9):1133–1143.
  4. Rewarding the return after a missed workout Milkman et al. 2021. See Chapter 11.
Ch. 13The Second New Year3
  1. Temporal landmarks across the year Dai, Milkman and Riis 2014. See Chapter 2.
  2. "Quitter's Day." Strava 2019 and 2020. See Chapter 1.
  3. How long habits take Singh et al. 2024. See Chapter 4.
BackWorksheets at the back of the book10
  1. Where to find help See Chapters 5, 6, 7, 8 and 9 (Riebe et al. 2015; ASAM 2020; Edinger et al. 2021).
  2. The Handover Note See Chapters 1, 2, 4, 5, 10, 11 and 12 (Gollwitzer and Sheeran 2006; Woolley and Fishbach 2017; Milkman et al. 2021).
  3. Looking back at last year's trip and reading the small print See Chapters 1 and 2 (Norcross and Vangarelli 1988; Buehler et al. 1994).
  4. Counting temptations and the friction map See Chapters 3 and 11 (Hofmann et al. 2012; Wood et al. 2002).
  5. The 66-box calendar See Chapter 4 (Lally et al. 2010; Singh et al. 2024).
  6. My weather forecast See Chapter 5 (Al Khatib et al. 2017, 2018; Schwabe and Wolf 2009).
  7. An "embarrassingly easy" first week See Chapter 6 (Ekkekakis et al. 2011; Rhodes and Kates 2015; Riebe et al. 2015).
  8. Old cue, new action See Chapters 7 and 8 (Wegner et al. 1987; Wood and Rünger 2016).
  9. Slow-motion replay and day-after plan See Chapter 12 (Marlatt and Gordon 1985; Adams and Leary 2007).
  10. My New Year's Days and the first twelve weeks See Chapters 9 and 13 (Dai et al. 2014; Edinger et al. 2021).
Cover of I Eat Mostly Plants. What Am I Missing?

Vol. 18

I Eat Mostly Plants. What Am I Missing?

Evidence last reviewed October 28, 2026 · review draft

Ch. 1I Eat Mostly Plants. What Am I Missing?6
  1. Planned vegetarian and vegan diets for adults Raj S, Guest NS, Landry MJ, Mangels AR, Pawlak R, Rozga M. Vegetarian dietary patterns for adults: a position of the Academy of Nutrition and Dietetics. J Acad Nutr Diet 2025;125(6):831–846.e2. This position does not cover pregnancy or breastfeeding.
  2. Nutrients that run lower in plant eaters Neufingerl N, Eilander A. Nutrient intake and status in adults consuming plant-based diets compared to meat-eaters: a systematic review. Nutrients 2021;14(1):29. doi:10.3390/nu14010029. Both authors are employees of Unilever, which sells fortified foods and supplements, as declared in the article.
  3. How many people eat plant-based diets in the US Gallup. In U.S., 4% identify as vegetarian, 1% as vegan. 2023. Academy of Nutrition and Dietetics, news release on the 2025 position, February 2025.
  4. Plant-based eating in Europe Smart Protein Project (ProVeg International, University of Copenhagen and partners). European consumer survey on plant-based foods.
  5. Vegetarianism in India Pew Research Center. Religion in India: Tolerance and Segregation. 2021.
  6. Seventh-day Adventists Orlich MJ, et al. Vegetarian dietary patterns and mortality in Adventist Health Study 2. JAMA Intern Med 2013. doi:10.1001/jamainternmed.2013.6473.
Ch. 2Five Lunches, Five Places3
  1. Who is most likely to be short of B12 Pawlak R, Parrott SJ, Raj S, Cullum-Dugan D, Lucus D. How prevalent is vitamin B12 deficiency among vegetarians? Nutr Rev 2013;71(2):110–117. doi:10.1111/nure.12001.
  2. B12 stores Rizzo G, Laganà AS, Rapisarda AMC, et al. Vitamin B12 among vegetarians: status, assessment and supplementation. Nutrients 2016;8(12):767.
  3. Tea and iron, iodine and plant milk, calcium in tofu, salt in plant-based burgers See Chapters 6, 8, 7 and 10.
Ch. 3The Plant Plate That Covers You4
  1. No need to combine proteins at each meal Mariotti F, Gardner CD. Dietary protein and amino acids in vegetarian diets: a review. Nutrients 2019;11(11):2661. doi:10.3390/nu11112661.
  2. Healthful and unhealthful plant-based diets and heart disease Satija A, Bhupathiraju SN, Spiegelman D, et al. Healthful and unhealthful plant-based diets and the risk of coronary heart disease in U.S. adults. J Am Coll Cardiol 2017;70(4):411–422.
  3. Fortified foods as a shield Eveleigh ER, Coneyworth LJ, Avery A, Welham SJM. Vegans, vegetarians, and omnivores: how does dietary choice influence iodine intake? A systematic review. Nutrients 2020;12(6):1606. doi:10.3390/nu12061606. Academy of Nutrition and Dietetics position, 2025 (see Chapter 1).
  4. Protein combining in popular books Lappé FM. Diet for a Small Planet. New York: Ballantine Books; 1971; tenth anniversary edition 1981.
Ch. 4B12: The One You Can't Skip8
  1. B12 deficiency in vegetarians and the need for a reliable source Pawlak et al. 2013. See Chapter 2. Raj et al. 2025. See Chapter 1.
  2. Forms and doses of B12 in vegans Fernandes S, Oliveira L, Pereira A, et al. Exploring vitamin B12 supplementation in the vegan population: a scoping review of the evidence. Nutrients 2024.
  3. Spirulina, seaweed, fermented foods and mushrooms Watanabe F, Yabuta Y, Bito T, Teng F. Vitamin B12-containing plant food sources for vegetarians. Nutrients 2014;6(5):1861–1873. doi:10.3390/nu6051861.
  4. Nori in a human study Yamada K, Yamada Y, Fukuda M, Yamada S. Bioavailability of dried asakusanori (Porphyra tenera) as a source of cobalamin. Int J Vitam Nutr Res 1999;69(6):412–418.
  5. Older vegetarians Foster M, Chu A, Samman S. Vegetarian nutrition for the older adult: vitamin B12, iron, and zinc. Curr Nutr Rep 2017;6(2):93–100.
  6. Metformin, acid-reducing medicines and testing Patel H, McGuirk R. Vitamin B12 deficiency: common questions and answers. Am Fam Physician 2025;112(3):294–300. Medicines and Healthcare products Regulatory Agency. Metformin and reduced vitamin B12 levels: new advice for monitoring patients at risk. Drug Safety Update, 2022.
  7. B12 and breastfeeding Centers for Disease Control and Prevention. Vitamin B12 and Breastfeeding.
  8. Nerve symptoms Rizzo et al. 2016. See Chapter 2.
Ch. 5Protein: The Biggest Worry, the Smallest Gap4
  1. Vegetarians and protein Mariotti and Gardner 2019. See Chapter 3. Neufingerl and Eilander 2021. See Chapter 1.
  2. Protein for older adults Bauer J, Biolo G, Cederholm T, et al. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. J Am Med Dir Assoc 2013;14(8):542–559. doi:10.1016/j.jamda.2013.05.021.
  3. Plant protein and resistance training Hevia-Larraín V, Gualano B, Longobardi I, et al. High-protein plant-based diet versus a protein-matched omnivorous diet to support resistance training adaptations: a comparison between habitual vegans and omnivores. Sports Med 2021. doi:10.1007/s40279-021-01434-9.
  4. Heavy metals in protein powder See Chapter 9.
Ch. 6Iron and Zinc: Enough on Paper, Low in the Blood5
  1. Iron stores, absorption, tea, vitamin C and phytate Saunders AV, Craig WJ, Baines SK, Posen JS. Iron and vegetarian diets. Med J Aust 2013;199(4 Suppl):S11–S16. doi:10.5694/mja11.11494. One author worked for Sanitarium, a plant-food company that sponsored the supplement in which this review appeared, as declared in the article.
  2. Iron status in vegetarian adults Pawlak R, Berger J, Hines I. Iron status of vegetarian adults: a review of literature. Am J Lifestyle Med 2016. doi:10.1177/1559827616682933.
  3. Vitamin C and iron absorption Heffernan A, Evans C, Holmes M, Moore JB. The regulation of dietary iron bioavailability by vitamin C: a systematic review and meta-analysis. Proc Nutr Soc 2017;76(OCE4):E182. doi:10.1017/S0029665117003445.
  4. Tea, coffee and iron absorption Hurrell RF, Reddy M, Cook JD. Inhibition of non-haem iron absorption in man by polyphenolic-containing beverages. Br J Nutr 1999;81(4):289–295.
  5. Zinc Foster M, Chu A, Petocz P, Samman S. Effect of vegetarian diets on zinc status: a systematic review and meta-analysis of studies in humans. J Sci Food Agric 2013;93(10):2362–2371. doi:10.1002/jsfa.6179. Foster et al. 2017. See Chapter 4.
Ch. 7Bones: The Study Plant Eaters Don't Like to Read3
  1. Fractures in EPIC-Oxford Tong TYN, Appleby PN, Armstrong MEG, et al. Vegetarian and vegan diets and risks of total and site-specific fractures: results from the prospective EPIC-Oxford study. BMC Med 2020;18(1):353. doi:10.1186/s12916-020-01815-3.
  2. Bone density and fractures in vegans Iguacel I, Miguel-Berges ML, Gómez-Bruton A, Moreno LA, Julián C. Veganism, vegetarianism, bone mineral density, and fracture risk: a systematic review and meta-analysis. Nutr Rev 2019;77(1):1–18. doi:10.1093/nutrit/nuy045.
  3. Calcium absorption from plant foods Weaver CM, Proulx WR, Heaney R. Choices for achieving adequate dietary calcium with a vegetarian diet. Am J Clin Nutr 1999;70(3 Suppl):543S–548S. Weaver CM, Plawecki KL. Dietary calcium: adequacy of a vegetarian diet. Am J Clin Nutr 1994;59(5 Suppl):1238S–1241S.
Ch. 8Iodine and Omega-3: The Quiet Two3
  1. Iodine in vegans, vegetarians and omnivores Eveleigh et al. 2020. See Chapter 3.
  2. Risks of excess iodine and kelp American Thyroid Association. ATA Statement on the Potential Risks of Excess Iodine Ingestion and Exposure. 2013, updated 2024.
  3. Omega-3 in vegetarians Saunders AV, Davis BC, Garg ML. Omega-3 polyunsaturated fatty acids and vegetarian diets. Med J Aust 2013;199(4 Suppl):S22–S26. doi:10.5694/mja11.11507. The lead author worked for Sanitarium, a plant-food company that sponsored the supplement in which this review appeared, as declared in the article. Neufingerl and Eilander 2021. See Chapter 1.
Ch. 9Keep the Worry or Drop It8
  1. Soy and breast cancer Wei Y, Lv J, Guo Y, et al. Soy intake and breast cancer risk: a prospective study of 300,000 Chinese women and a dose–response meta-analysis. Eur J Epidemiol 2020;35:567–578. doi:10.1007/s10654-019-00585-4. Shu XO, Zheng Y, Cai H, et al. Soy food intake and breast cancer survival. JAMA 2009;302(22):2437–2443.
  2. Soy and male hormones Reed KE, Camargo J, Hamilton-Reeves J, Kurzer M, Messina M. Neither soy nor isoflavone intake affects male reproductive hormones: an expanded and updated meta-analysis of clinical studies. Reprod Toxicol 2021;100:60–67. doi:10.1016/j.reprotox.2020.12.019. Co-author Mark Messina is executive director of the Soy Nutrition Institute and has consulted for the United Soybean Board.
  3. Lectins in dried beans Health Canada. Lectins in Dry Legumes.
  4. Oxalates and kidney stones North Bristol NHS Trust. Additional Information if You Form Calcium Oxalate Stones.
  5. Arsenic in rice Harvard Health Publishing, reporting US Food and Drug Administration advice on arsenic in rice, 2016.
  6. Lead in protein powders Consumer Reports. Protein powder and shake testing. October 2025.
  7. Plant-based eating and disordered eating McLean CP, Kulkarni J, Sharp G. Disordered eating and the meat-avoidance spectrum: a systematic review and clinical implications. Eat Weight Disord 2022;27(7):2347–2375. doi:10.1007/s40519-022-01428-0.
  8. Weight change in trials Wang et al. 2023. See Chapter 11.
Ch. 10Mock Meat: Plant Food or Ultra-Processed Food?12
  1. Defining ultra-processed food Monteiro CA, Cannon G, Levy RB, et al. Ultra-processed foods: what they are and how to identify them. Public Health Nutr 2019;22(5):936–941.
  2. Ultra-processed food and health outcomes Lane MM, Gamage E, Du S, et al. Ultra-processed food exposure and adverse health outcomes: umbrella review of epidemiological meta-analyses. BMJ 2024;384:e077310. doi:10.1136/bmj-2023-077310.
  3. Ultra-processed diets and calorie intake Hall KD, Ayuketah A, Brychta R, et al. Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake. Cell Metab 2019;30(1):67–77.
  4. Plant foods, processing and heart disease Rauber F, Louzada MLC, Chang K, et al. Implications of food ultra-processing on cardiovascular risk considering plant origin foods: an analysis of the UK Biobank cohort. Lancet Reg Health Eur 2024. doi:10.1016/j.lanepe.2024.100948.
  5. Salt in meat alternatives Action on Salt. Meat Alternatives Survey. October 2018.
  6. Labelling of packaged vegetarian meat Consumer Council, Hong Kong. Vegetarian meat. CHOICE magazine, press release, 15 August 2019.
  7. Vegetarian restaurant dishes Centre for Food Safety and Consumer Council, Hong Kong. Sodium, Sugar, Fat and Energy Contents in Local Vegetarian Dishes. February 2021.
  8. Fortification and salt in plant-based meats The Food Foundation. Rethinking Plant-Based Meat Alternatives. August 2024.
  9. Nutritional profile of plant-based meats Wu J, El Sadig R. Are novel plant-based meat alternatives the healthier choice? Food Res Int 2024;183:114184. doi:10.1016/j.foodres.2024.114184.
  10. Swapping meat for plant-based meat: trials Crimarco A, Springfield S, Petlura C, et al. A randomized crossover trial on the effect of plant-based compared with animal-based meat on trimethylamine-N-oxide and cardiovascular disease risk factors in generally healthy adults: Study With Appetizing Plantfood—Meat Eating Alternative Trial (SWAP-MEAT). Am J Clin Nutr 2020. doi:10.1093/ajcn/nqaa203. Funded by Beyond Meat; the analysis plan was registered in advance and the analysis was done independently. Toh DWK, Fu AS, et al. Plant-based meat analogs and their effects on cardiometabolic health: an 8-week randomized controlled trial comparing plant-based meat analogs with their corresponding animal-based foods. Am J Clin Nutr 2024. doi:10.1016/j.ajcnut.2024.04.006.
  11. Seizure of expired mock meat Pháp luật Việt Nam newspaper, 21 October 2020.
  12. Salt limit World Health Organization. Guideline: Sodium Intake for Adults and Children. Geneva: WHO; 2012.
Ch. 11Heart, Blood Sugar, Weight: How Real Are the Benefits?6
  1. Heart disease and stroke in EPIC-Oxford Tong TYN, Appleby PN, Bradbury KE, et al. Risks of ischaemic heart disease and stroke in meat eaters, fish eaters, and vegetarians over 18 years of follow-up: results from the prospective EPIC-Oxford study. BMJ 2019;366:l4897. doi:10.1136/bmj.l4897.
  2. Pooled cohort studies Dybvik JS, Svendsen M, Aune D. Vegetarian and vegan diets and the risk of cardiovascular disease, ischemic heart disease and stroke: a systematic review and meta-analysis of prospective cohort studies. Eur J Nutr 2023;62(1):51–69. doi:10.1007/s00394-022-02942-8.
  3. Adventist Health Study 2 Orlich et al. 2013. See Chapter 1.
  4. Trials of vegetarian diets Wang T, Kroeger CM, Cassidy S, et al. Vegetarian dietary patterns and cardiometabolic risk in people with or at high risk of cardiovascular disease: a systematic review and meta-analysis. JAMA Netw Open 2023;6(7):e2325658. doi:10.1001/jamanetworkopen.2023.25658.
  5. Healthful and unhealthful plant-based diets and type 2 diabetes Satija A, Bhupathiraju SN, Rimm EB, et al. Plant-based dietary patterns and incidence of type 2 diabetes in US men and women: results from three prospective cohort studies. PLoS Med 2016;13(6):e1002039. Qian F, Liu G, Hu FB, Bhupathiraju SN, Sun Q. Association between plant-based dietary patterns and risk of type 2 diabetes: a systematic review and meta-analysis. JAMA Intern Med 2019;179(10):1335–1344. UK Biobank analysis of plant-based diet indices and type 2 diabetes in 113,097 adults.
  6. Vegetarian diets and diabetes in India Analysis of the National Family Health Survey (NFHS-3, 2005–2006). Nutr J 2014;13:89. doi:10.1186/1475-2891-13-89.
Ch. 12Reading Rachel's Blood Test5
  1. B12 cut-offs, MMA and who to test Patel and McGuirk 2025. See Chapter 4.
  2. Ferritin and iron stores World Health Organization. WHO Guideline on Use of Ferritin Concentrations to Assess Iron Status in Individuals and Populations. Geneva: WHO; 2020.
  3. Hair mineral analysis Seidel S, Kreutzer R, Smith D, McNeel S, Gilliss D. Assessment of commercial laboratories performing hair mineral analysis. JAMA 2001;285(1):67–72.
  4. IgG food tests Carr S, Chan E, Lavine E, Moote W. CSACI position statement on the testing of food-specific IgG. Allergy Asthma Clin Immunol 2012;8(1):12. Association for Diagnostics and Laboratory Medicine. Optimal Testing Guide.
  5. Biotin and lab tests US Food and Drug Administration. Safety communication on biotin interference with laboratory tests.
Ch. 13Starting, Switching, and Eating With Everyone Else5
  1. Why people stop eating vegetarian Faunalytics. Study of Current and Former Vegetarians and Vegans. 2014. Faunalytics is a research organisation that serves the animal-protection movement.
  2. Beans and gas Winham DM, Hutchins AM. Perceptions of flatulence from bean consumption among adults in 3 feeding studies. Nutr J 2011;10:128. doi:10.1186/1475-2891-10-128. UCLA Health, patient information on beans and gas.
  3. Pregnancy and breastfeeding Academy of Nutrition and Dietetics position, 2025 (see Chapter 1). Centers for Disease Control and Prevention. Vitamin B12 and Breastfeeding.
  4. Warfarin and vitamin K Cambridge University Hospitals NHS Foundation Trust. Patient information for people taking warfarin.
  5. Plant-based diets in chronic kidney disease Ikizler TA, Burrowes JD, Byham-Gray LD, et al. KDOQI clinical practice guideline for nutrition in CKD: 2020 update. Am J Kidney Dis 2020;76(3 Suppl 1):S1–S107.
Ch. 14Your Minimum Kit1
  1. The five things in the Minimum Kit See the sources for Chapters 3, 4, 5, 6, 7 and 8.
BackWorksheets and kitchen section at the back of the book5
  1. Kitchen section, menus and recipes Built on the five-part plate (Chapter 3) and the Minimum Kit (Chapter 14). Kidney bean safety: Health Canada (Chapter 9). Kombu and iodine: American Thyroid Association (Chapter 8).
  2. Blind-Spot Map and personal Minimum Kit See Chapters 1 and 14.
  3. The plant plate and moving tea time See Chapters 3 and 6.
  4. The card for your doctor See Chapter 12 (Patel and McGuirk 2025; WHO 2020).
  5. Four-week diary See Chapter 14.
Your Body, DecodedVol. 19 Is It Stress, or Is It Something Else? An Thanh Tùng

Vol. 19

Is It Stress, or Is It Something Else?

Evidence last reviewed October 29, 2026 · review draft

Ch. 1One Sentence, Four Endings3
  1. What happens to people who see a doctor about tiredness Nijrolder I, van der Windt D, de Vries H, van der Horst H. Diagnoses during follow-up of patients presenting with fatigue in primary care. CMAJ 2009;181(10):683–687. doi:10.1503/cmaj.090647. PMID 19858240.
  2. Iron and fatigue without anaemia Houston BL, Hurrie D, Graham J, et al. Efficacy of iron supplementation on fatigue and physical capacity in non-anaemic iron-deficient adults: a systematic review of randomised controlled trials. BMJ Open 2018;8(4):e019240. doi:10.1136/bmjopen-2017-019240. PMID 29626044.
  3. Sleep apnoea in women Bouloukaki I, Tsiligianni I, Schiza S. Evaluation of obstructive sleep apnea in female patients in primary care: time for improvement? Med Princ Pract 2021;30(6):508–514. doi:10.1159/000518932. PMID 34438402.
Ch. 2What Stress Really Does (and Doesn't)2
  1. "Adrenal fatigue" Cadegiani FA, Kater CE. Adrenal fatigue does not exist: a systematic review. BMC Endocr Disord 2016;16(1):48. doi:10.1186/s12902-016-0128-4. PMID 27557747.
  2. Burn-out in ICD-11 World Health Organization. Burn-out an "occupational phenomenon": International Classification of Diseases. News release, May 28, 2019.
Ch. 3Racing Heart, Shaky Hands, Sweats3
  1. Overactive thyroid Ross DS, Burch HB, Cooper DS, et al. 2016 American Thyroid Association guidelines for diagnosis and management of hyperthyroidism and other causes of thyrotoxicosis. Thyroid 2016;26(10):1343–1421. doi:10.1089/thy.2016.0229. PMID 27521067.
  2. Rhythm disorders mistaken for panic Lessmeier TJ, Gamperling D, Johnson-Liddon V, et al. Unrecognized paroxysmal supraventricular tachycardia: potential for misdiagnosis as panic disorder. Arch Intern Med 1997;157(5):537–543. PMID 9066458.
  3. Caffeine EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific opinion on the safety of caffeine. EFSA J 2015;13(5):4102.
Ch. 4Tired All the Time4
  1. Iron and fatigue without anaemia Houston et al. 2018. See Chapter 1.
  2. Underactive thyroid Chaker L, Bianco AC, Jonklaas J, Peeters RP. Hypothyroidism. Lancet 2017;390(10101):1550–1562. doi:10.1016/S0140-6736(17)30703-130703-1). PMID 28336049.
  3. Iron-deficiency anaemia Camaschella C. Iron-deficiency anemia. N Engl J Med 2015;372(19):1832–1843. doi:10.1056/NEJMra1401038. PMID 25946282.
  4. Ferritin cut-offs Ko CW, Siddique SM, Patel A, et al. AGA clinical practice guidelines on the gastrointestinal evaluation of iron deficiency anemia. Gastroenterology 2020;159(3):1085–1094. doi:10.1053/j.gastro.2020.06.046. PMID 32810434.
Ch. 5Poor Sleep: Stress or Breathing?5
  1. Treatment of sleep apnoea Patil SP, Ayappa IA, Caples SM, et al. Treatment of adult obstructive sleep apnea with positive airway pressure: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment. J Clin Sleep Med 2019;15(2):301–334. doi:10.5664/jcsm.7638. PMID 30736888.
  2. Sleep apnoea: features and risk factors Jordan AS, McSharry DG, Malhotra A. Adult obstructive sleep apnoea. Lancet 2014;383(9918):736–747. doi:10.1016/S0140-6736(13)60734-560734-5). PMID 23910433.
  3. Screening people without symptoms US Preventive Services Task Force. Screening for obstructive sleep apnea in adults: US Preventive Services Task Force recommendation statement. JAMA 2022;328(19):1945–1950. doi:10.1001/jama.2022.20304. PMID 36378202.
  4. Sleep apnoea in women Bouloukaki et al. 2021. See Chapter 1.
  5. Restless legs and iron Winkelman JW, Berkowski JA, DelRosso LM, et al. Treatment of restless legs syndrome and periodic limb movement disorder: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med 2025;21(1):137–152. doi:10.5664/jcsm.11390. PMID 39324694.
Ch. 6Anxious, Keyed Up, Panicky5
  1. Treating anxiety disorders Bandelow B, Michaelis S, Wedekind D. Treatment of anxiety disorders. Dialogues Clin Neurosci 2017;19(2):93–107. doi:10.31887/DCNS.2017.19.2/bbandelow. PMID 28867934.
  2. CBT compared with placebo Carpenter JK, Andrews LA, Witcraft SM, et al. Cognitive behavioral therapy for anxiety and related disorders: a meta-analysis of randomized placebo-controlled trials. Depress Anxiety 2018;35(6):502–514. doi:10.1002/da.22728. PMID 29451967.
  3. Screening for anxiety US Preventive Services Task Force. Screening for anxiety disorders in adults: US Preventive Services Task Force recommendation statement. JAMA 2023;329(24):2163–2170. doi:10.1001/jama.2023.9301. PMID 37338866.
  4. The GAD-7 Spitzer RL, Kroenke K, Williams JBW, Löwe B. A brief measure for assessing generalized anxiety disorder: the GAD-7. Arch Intern Med 2006;166(10):1092–1097. doi:10.1001/archinte.166.10.1092. PMID 16717171.
  5. Rhythm disorders mistaken for panic Lessmeier et al. 1997. See Chapter 3.
Ch. 7Brain Fog and Forgetting3
  1. Vitamin B12 deficiency Stabler SP. Vitamin B12 deficiency. N Engl J Med 2013;368(2):149–160. doi:10.1056/NEJMcp1113996. PMID 23301732.
  2. Sleep apnoea and cognition US Preventive Services Task Force 2022. See Chapter 5.
  3. Medicines in older adults American Geriatrics Society Beers Criteria Update Expert Panel. American Geriatrics Society 2023 updated AGS Beers Criteria for potentially inappropriate medication use in older adults. J Am Geriatr Soc 2023;71(7):2052–2081. doi:10.1111/jgs.18372. PMID 37139824.
Ch. 8Midlife: Stress, or Perimenopause?3
  1. Diagnosing perimenopause National Institute for Health and Care Excellence. Menopause. Quality standard QS143, quality statement 1; based on NICE guideline NG23, Menopause: identification and management.
  2. Stages of reproductive ageing Harlow SD, Gass M, Hall JE, et al. Executive summary of the Stages of Reproductive Aging Workshop + 10: addressing the unfinished agenda of staging reproductive aging. Menopause 2012;19(4):387–395. doi:10.1097/gme.0b013e31824d8f40. PMID 22343510.
  3. Heavy periods and iron Camaschella 2015. See Chapter 4.
Ch. 9Men at Midlife: Stress, Low Testosterone, or Something Else?4
  1. Diagnosing and treating testosterone deficiency Bhasin S, Brito JP, Cunningham GR, et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2018;103(5):1715–1744. doi:10.1210/jc.2018-00229. PMID 29562364.
  2. Weight loss and testosterone Corona G, Rastrelli G, Monami M, et al. Body weight loss reverts obesity-associated hypogonadotropic hypogonadism: a systematic review and meta-analysis. Eur J Endocrinol 2013;168(6):829–843. doi:10.1530/EJE-12-0955. PMID 23482592.
  3. Testosterone and the heart: the TRAVERSE trial Lincoff AM, Bhasin S, Flevaris P, et al. Cardiovascular safety of testosterone-replacement therapy. N Engl J Med 2023;389(2):107–117. doi:10.1056/NEJMoa2215025. PMID 37326322.
  4. Depression in men Martin LA, Neighbors HW, Griffith DM. The experience of symptoms of depression in men vs women: analysis of the National Comorbidity Survey Replication. JAMA Psychiatry 2013;70(10):1100–1106. doi:10.1001/jamapsychiatry.2013.1985. PMID 23986338.
Ch. 10Warning Signs: Symptoms Never to Blame on Stress Before They're Checked5
  1. Chest pain National Institute for Health and Care Excellence. Recent-onset chest pain of suspected cardiac origin: assessment and diagnosis. Clinical guideline CG95; 2010, updated 2016.
  2. Stroke National Institute for Health and Care Excellence. Stroke and transient ischaemic attack in over 16s: diagnosis and initial management. NICE guideline NG128; 2019, updated 2022.
  3. Fainting National Institute for Health and Care Excellence. Transient loss of consciousness ('blackouts') in over 16s. Clinical guideline CG109; 2010, updated 2023.
  4. Weight loss, bleeding, difficulty swallowing, persistent fatigue National Institute for Health and Care Excellence. Suspected cancer: recognition and referral. NICE guideline NG12; 2015, updated 2026.
  5. Weight loss as a warning sign Nicholson BD, Hamilton W, O'Sullivan J, et al. Weight loss as a predictor of cancer in primary care: a systematic review and meta-analysis. Br J Gen Pract 2018;68(670):e311–e322. doi:10.3399/bjgp18X695801. PMID 29632004.
Ch. 11The Look-Alikes in Your Cup and Cabinet4
  1. Caffeine EFSA 2015. See Chapter 3.
  2. Alcohol and sleep Ebrahim IO, Shapiro CM, Williams AJ, Fenwick PB. Alcohol and sleep I: effects on normal sleep. Alcohol Clin Exp Res 2013;37(4):539–549. doi:10.1111/acer.12006. PMID 23347102.
  3. Restless legs and what makes them worse Winkelman et al. 2025. See Chapter 5.
  4. Hormones in "adrenal support" supplements Akturk HK, Chindris AM, Hines JM, et al. Over-the-counter "adrenal support" supplements contain thyroid and steroid-based adrenal hormones. Mayo Clin Proc 2018;93(3):284–290. doi:10.1016/j.mayocp.2017.10.019. PMID 29502560.
Ch. 12A Letter to Someone With Normal Results4
  1. Tiredness without a diagnosis Nijrolder et al. 2009. See Chapter 1.
  2. ME/CFS National Institute for Health and Care Excellence. Myalgic encephalomyelitis (or encephalopathy)/chronic fatigue syndrome: diagnosis and management. NICE guideline NG206; 2021.
  3. Physical activity and mood Singh B, Olds T, Curtis R, et al. Effectiveness of physical activity interventions for improving depression, anxiety and distress: an overview of systematic reviews. Br J Sports Med 2023;57(18):1203–1209. doi:10.1136/bjsports-2022-106195. PMID 36796860.
  4. Psychological therapy for unexplained physical symptoms van Dessel N, den Boeft M, van der Wouden JC, et al. Non-pharmacological interventions for somatoform disorders and medically unexplained physical symptoms (MUPS) in adults. Cochrane Database Syst Rev 2014;(11):CD011142. doi:10.1002/14651858.CD011142.pub2. PMID 25362239.
Ch. 13How to Be Heard, and Tests You Don't Need4
  1. Safety netting NICE guideline NG12, recommendation 1.15.2. See Chapter 10.
  2. Saliva cortisol and "adrenal fatigue" Cadegiani and Kater 2016. See Chapter 2.
  3. Hormone tests for perimenopause NICE quality standard QS143. See Chapter 8.
  4. Screening for sleep apnoea US Preventive Services Task Force 2022. See Chapter 5.
Ch. 14Your Three-Lane Plan1
  1. Safety netting NICE guideline NG12, recommendation 1.15.2. See Chapter 10.
BackWorksheets at the back of the book8
  1. When to call emergency services See Chapter 10 (NICE CG95, NG128, CG109, NG12).
  2. Where to find help 988 Suicide and Crisis Lifeline (US, Canada); Samaritans (UK, Ireland); Lifeline (Australia); 1737 (New Zealand); findahelpline.com.
  3. Three-lane worksheet, 14-day diary, appointment sheet, four-week plan This book's own tools, built from Chapters 1, 4, 13 and 14 (NICE NG12 on safety netting).
  4. Worksheets 5a and 5b Written for this book; they are not the Epworth Sleepiness Scale or the STOP-Bang questionnaire and give no score. See Chapter 5 (Jordan et al. 2014).
  5. Resting pulse and episode log See Chapter 3 (Lessmeier et al. 1997).
  6. GAD-7 score sheet Spitzer et al. 2006. See Chapter 6.
  7. Cup and cabinet inventory See Chapter 11.
  8. Three-month cycle calendar See Chapter 8.
Cover of Is My Wearable Lying to Me?

Vol. 20

Is My Wearable Lying to Me?

Evidence last reviewed October 27, 2026

Ch. 1One Night, Two Numbers2
  1. Accuracy differs by kind of number Doherty C, Baldwin M, Keogh A, Caulfield B, Argent R. Keeping pace with wearables: a living umbrella review of systematic reviews evaluating the accuracy of consumer wearable technologies in health measurement. Sports Med 2024;54(11):2907–2926. doi:10.1007/s40279-024-02077-2. PMID 39080098.
  2. Composite scores use unpublished formulas Doherty C, Baldwin M, Lambe R, Burke D, Altini M. Readiness, recovery, and strain: an evaluation of composite health scores in consumer wearables. Transl Exerc Biomed 2025;2(2):128–144. doi:10.1515/teb-2025-0001.
Ch. 2Inside the Machine4
  1. Movement, skin tone and wrist heart rate Bent B, Goldstein BA, Kibbe WA, Dunn JP. Investigating sources of inaccuracy in wearable optical heart rate sensors. NPJ Digit Med 2020;3:18. doi:10.1038/s41746-020-0226-6. PMID 32047863.
  2. Error by sex, body size and skin tone Shcherbina A, Mattsson CM, Waggott D, et al. Accuracy in wrist-worn, sensor-based measurements of heart rate and energy expenditure in a diverse cohort. J Pers Med 2017;7(2):3. doi:10.3390/jpm7020003. PMID 28538708.
  3. Accuracy overview Doherty et al. 2024. See Chapter 1.
  4. How to wear a device Apple Support. Get the most accurate measurements using your Apple Watch (article 105002); Garmin. Tips for Erratic Heart Rate Data (fēnix 8 owner's manual); Oura Member Care. Ring sizing and finger guidance. All checked October 27, 2026.
Ch. 3Who Checks the Checker?9
  1. Algorithms change faster than studies; few devices validated Doherty et al. 2024. See Chapter 1.
  2. Authorized features and wellness features US Food and Drug Administration. General Wellness: Policy for Low Risk Devices. Final guidance, January 2026. Docket FDA-2014-N-1039.
  3. Wake detection in a validation study Chinoy ED, Cuellar JA, Huwa KE, et al. Performance of seven consumer sleep-tracking devices compared with polysomnography. Sleep 2021;44(5):zsaa291. doi:10.1093/sleep/zsaa291. PMID 33378539.
  4. A small validation study Dial MB, Hollander ME, Vatne EA, Emerson AM, Edwards NA, Hagen JA. Validation of nocturnal resting heart rate and heart rate variability in consumer wearables. Physiol Rep 2025;13(16):e70527. doi:10.14814/phy2.70527. PMID 40834291.
  5. Who funds the study Perez MV, Mahaffey KW, Hedlin H, et al. Large-scale assessment of a smartwatch to identify atrial fibrillation. N Engl J Med 2019;381(20):1909–1917. doi:10.1056/NEJMoa1901183. PMID 31722151. Miller DJ, Sargent C, Roach GD. A validation of six wearable devices for estimating sleep, heart rate and heart rate variability in healthy adults. Sensors (Basel) 2022;22(16):6317. doi:10.3390/s22166317. PMID 36016077. Maijala A, Kinnunen H, Koskimäki H, Jämsä T, Kangas M. Nocturnal finger skin temperature in menstrual cycle tracking: ambulatory pilot study using a wearable Oura ring. BMC Womens Health 2019;19(1):150. doi:10.1186/s12905-019-0844-9. PMID 31783840.
  6. A correction that changed a comparison Barrera N, Solorzano M, Jimenez Y, et al. Accuracy of smartwatches in the detection of atrial fibrillation: a systematic review and diagnostic meta-analysis. JACC Adv 2025;4(11 Pt 1):102133. doi:10.1016/j.jacadv.2025.102133. PMID 41182224. Correction: JACC Adv 2026;5(5):102728. PMID 42012426.
  7. VO2 max error Lambe R, O'Grady B, Baldwin M, Doherty C. Investigating the accuracy of Apple Watch VO2 max measurements: a validation study. PLoS One 2025;20(5):e0323741. doi:10.1371/journal.pone.0323741. PMID 40373042.
  8. Sensitivity and specificity of a hypertension alert US Food and Drug Administration. 510(k) summary K250507, Apple Hypertension Notification Feature, September 11, 2025.
  9. Kappa for sleep stages Schyvens AM, Peters B, Van Oost NC, et al. A performance validation of six commercial wrist-worn wearable sleep-tracking devices for sleep stage scoring compared to polysomnography. Sleep Adv 2025;6(2):zpaf021. doi:10.1093/sleepadvances/zpaf021. PMID 40303381.
Ch. 4Heart Rate5
  1. Resting and steady-exercise heart rate accuracy Doherty et al. 2024. See Chapter 1. Shcherbina et al. 2017. See Chapter 2.
  2. Weights, intervals and fast changes Bent et al. 2020. See Chapter 2.
  3. "220 minus age." Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. J Am Coll Cardiol 2001;37(1):153–156. doi:10.1016/s0735-1097(00)01054-801054-8). PMID 11153730.
  4. Resting heart rate and mortality Zhang D, Shen X, Qi X. Resting heart rate and all-cause and cardiovascular mortality in the general population: a meta-analysis. CMAJ 2016;188(3):E53–E63. doi:10.1503/cmaj.150535. PMID 26598376.
  5. Normal resting heart rate varies between people Quer G, Gouda P, Galarnyk M, Topol EJ, Steinhubl SR. Inter- and intraindividual variability in daily resting heart rate and its associations with age, sex, sleep, BMI, and time of year: retrospective, longitudinal cohort study of 92,457 adults. PLoS One 2020;15(2):e0227709. doi:10.1371/journal.pone.0227709. PMID 32023264.
Ch. 5When the Rhythm Is Off4
  1. The Apple Heart Study Perez et al. 2019. See Chapter 3.
  2. Pooled accuracy for atrial fibrillation Barrera et al. 2025, and correction 2026. See Chapter 3.
  3. Screening for atrial fibrillation US Preventive Services Task Force. Screening for Atrial Fibrillation. Final recommendation statement, January 25, 2022.
  4. What a watch ECG cannot detect Apple Support. Take an ECG with the ECG app on Apple Watch (article 120278). Checked October 27, 2026.
Ch. 6Steps and Movement5
  1. Step-count accuracy Doherty et al. 2024. See Chapter 1.
  2. Steps and mortality Paluch AE, Bajpai S, Bassett DR, et al. Daily steps and all-cause mortality: a meta-analysis of 15 international cohorts. Lancet Public Health 2022;7(3):e219–e228. doi:10.1016/S2468-2667(21)00302-900302-9). PMID 35247352.
  3. Where 10,000 came from Tudor-Locke C, Bassett DR Jr. How many steps/day are enough? Preliminary pedometer indices for public health. Sports Med 2004;34(1):1–8. doi:10.2165/00007256-200434010-00001. PMID 14715035.
  4. Steps in older women Lee IM, Shiroma EJ, Kamada M, et al. Association of step volume and intensity with all-cause mortality in older women. JAMA Intern Med 2019;179(8):1105–1112. doi:10.1001/jamainternmed.2019.0899. PMID 31141585.
  5. Trackers help people move more Ferguson T, Olds T, Curtis R, et al. Effectiveness of wearable activity trackers to increase physical activity and improve health: a systematic review of systematic reviews and meta-analyses. Lancet Digit Health 2022;4(8):e615–e626. doi:10.1016/S2589-7500(22)00111-X00111-X). PMID 35868813.
Ch. 7Calories Burned2
  1. The Stanford study Shcherbina et al. 2017. See Chapter 2. Median error range by device as reported in Healio's summary of the study.
  2. Average bias across reviews Doherty et al. 2024. See Chapter 1.
Ch. 8Sleep: Hours, Stages and Scores5
  1. Sleep and wake detection Chinoy et al. 2021. See Chapter 3. Schyvens et al. 2025. See Chapter 3. Doherty et al. 2024. See Chapter 1.
  2. Sleep stages Miller et al. 2022. See Chapter 3. Schyvens AM, Van Oost NC, Aerts JM, et al. Accuracy of Fitbit Charge 4, Garmin Vivosmart 4, and WHOOP versus polysomnography: systematic review. JMIR Mhealth Uhealth 2024;12:e52192. doi:10.2196/52192. PMID 38557808.
  3. Devices and insomnia Dong X, Yang S, Guo Y, et al. Validation of Fitbit Charge 4 for assessing sleep in Chinese patients with chronic insomnia: a comparison against polysomnography and actigraphy. PLoS One 2022;17(10):e0275287. doi:10.1371/journal.pone.0275287. PMID 36256631.
  4. Sleep regularity Sletten TL, Weaver MD, Foster RG, et al. The importance of sleep regularity: a consensus statement of the National Sleep Foundation sleep timing and variability panel. Sleep Health 2023;9(6):801–820. doi:10.1016/j.sleh.2023.07.016. PMID 37684151. Windred DP, Burns AC, Lane JM, et al. Sleep regularity is a stronger predictor of mortality risk than sleep duration: a prospective cohort study. Sleep 2024;47(1):zsad253. doi:10.1093/sleep/zsad253. PMID 37738616.
  5. Sleep scores as composite scores Doherty et al. 2025. See Chapter 1.
Ch. 9HRV, Readiness, Recovery and Stress5
  1. Composite scores Doherty et al. 2025. See Chapter 1.
  2. Overnight HRV accuracy Dial et al. 2025. See Chapter 3.
  3. HRV and cardiovascular events Hillebrand S, Gast KB, de Mutsert R, et al. Heart rate variability and first cardiovascular event in populations without known cardiovascular disease: meta-analysis and dose-response meta-regression. Europace 2013;15(5):742–749. doi:10.1093/europace/eus341. PMID 23370966.
  4. Raising device HRV PubMed search, October 27, 2026: no trials found linking efforts to raise wearable HRV with health outcomes.
  5. Slow-breathing training with heart rate feedback Lehrer P, Kaur K, Sharma A, et al. Heart rate variability biofeedback improves emotional and physical health and performance: a systematic review and meta analysis. Appl Psychophysiol Biofeedback 2020;45(3):109–129. doi:10.1007/s10484-020-09466-z. PMID 32385728.
Ch. 10Night Signals: Oxygen, Breathing, Temperature and Cycles7
  1. Skin tone and pulse oximetry Sjoding MW, Dickson RP, Iwashyna TJ, Gay SE, Valley TS. Racial bias in pulse oximetry measurement. N Engl J Med 2020;383(25):2477–2478. doi:10.1056/NEJMc2029240. PMID 33326721. Valbuena VSM, Seelye S, Sjoding MW, et al. Racial bias and reproducibility in pulse oximetry among medical and surgical inpatients in general care in the Veterans Health Administration 2013–19: multicenter, retrospective cohort study. BMJ 2022;378:e069775. doi:10.1136/bmj-2021-069775. PMID 35793817. US Food and Drug Administration. Pulse Oximeters for Medical Purposes: Non-Clinical and Clinical Performance Testing, Labeling, and Premarket Submission Recommendations. Draft guidance, January 2025.
  2. Wearable blood oxygen error Doherty et al. 2024. See Chapter 1.
  3. Limits of oximeters US Food and Drug Administration. Safety communication on pulse oximeter accuracy and limitations, February 2021.
  4. Sleep apnea alerts Apple. Sleep Apnea Notifications on Apple Watch, September 2024; US Food and Drug Administration 510(k) K240929.
  5. Skin temperature and the menstrual cycle Maijala et al. 2019. See Chapter 3.
  6. Contraception apps US Food and Drug Administration. News release on the first direct-to-consumer app for contraception, August 2018; 510(k) K202897 (2021).
  7. Early signs of infection Mishra T, Wang M, Metwally AA, et al. Pre-symptomatic detection of COVID-19 from smartwatch data. Nat Biomed Eng 2020;4(12):1208–1220. doi:10.1038/s41551-020-00640-6. PMID 33208926.
Ch. 11Blood Pressure, Blood Sugar and Body Composition6
  1. Non-invasive blood sugar US Food and Drug Administration. Do Not Use Smartwatches or Smart Rings to Measure Blood Glucose Levels. Safety communication, February 21, 2024.
  2. Cuffless blood pressure US Food and Drug Administration. Do Not Use Unauthorized Devices for Measuring Blood Pressure. Safety communication, September 16, 2025. FDA General Wellness guidance, January 2026. See Chapter 3.
  3. Hypertension alert accuracy FDA 510(k) K250507. See Chapter 3. Houston Methodist commentary on the hypertension notification, May 2026.
  4. Measuring blood pressure at home Parati G, Stergiou GS, Bilo G, et al. Home blood pressure monitoring: methodology, clinical relevance and practical application: a 2021 position paper by the Working Group on Blood Pressure Monitoring and Cardiovascular Variability of the European Society of Hypertension. J Hypertens 2021;39(9):1742–1767. doi:10.1097/HJH.0000000000002922. PMID 34269334. Validated monitor list: validatebp.org (American Medical Association).
  5. Watch body composition Carrier B, Melvin AC, Outwin JR, et al. Wearables for health monitoring: body composition estimates of commercial smartwatch and clinical bioelectrical impedance device. Front Sports Act Living 2025;7:1644082. doi:10.3389/fspor.2025.1644082. PMID 41341278. Bennett JP, Liu YE, Kelly NN, et al. Next-generation smart watches to estimate whole-body composition using bioimpedance analysis: accuracy and precision in a diverse, multiethnic sample. Am J Clin Nutr 2022;116(5):1418–1429. doi:10.1093/ajcn/nqac200. PMID 35883219.
  6. Bioimpedance and implanted devices Ha GB, Steinberg BA, Freedman R, Bayés-Genís A, Sanchez B. Safety evaluation of smart scales, smart watches, and smart rings with bioimpedance technology shows evidence of potential interference in cardiac implantable electronic devices. Heart Rhythm 2023;20(4):561–571. doi:10.1016/j.hrthm.2022.11.026. PMID 36997272. Hansen N, Sheppard T, McCoy J, et al. Smartwatches and smart scales with body composition may interfere with cardiac implantable electronic devices. Circ Arrhythm Electrophysiol 2025;18(12):e013881. doi:10.1161/CIRCEP.125.013881. PMID 41328543. Uribe-Cavero LJ, Chavez-Ecos FA, Camacho-Caballero K, et al. Safety of bioelectrical impedance analysis in patients with cardiac implantable electronic devices: a systematic review. Heart Rhythm O2 2025;6(12):1985–1992. doi:10.1016/j.hroo.2025.09.026. PMID 41541720. Samsung Support. Body composition measurement guidance. Checked October 27, 2026.
Ch. 12Fitness, Age Scores and CGMs5
  1. Fitness and mortality Kodama S, Saito K, Tanaka S, et al. Cardiorespiratory fitness as a quantitative predictor of all-cause mortality and cardiovascular events in healthy men and women: a meta-analysis. JAMA 2009;301(19):2024–2035. doi:10.1001/jama.2009.681. PMID 19454641.
  2. Wearable VO2 max Doherty et al. 2024. See Chapter 1. Lambe et al. 2025. See Chapter 3.
  3. "Age" scores PubMed search, October 27, 2026: no independent validation of any brand's "age" score found.
  4. Training load and recovery scores Doherty et al. 2025. See Chapter 1.
  5. CGMs in healthy people Shah VN, DuBose SN, Li Z, et al. Continuous glucose monitoring profiles in healthy nondiabetic participants: a multicenter prospective study. J Clin Endocrinol Metab 2019;104(10):4356–4364. doi:10.1210/jc.2018-02763. PMID 31127824. Healio. Report of an expert presentation on CGM use in people without diabetes, January 20, 2026.
Ch. 13Data Anxiety7
  1. Orthosomnia Baron KG, Abbott S, Jao N, Manalo N, Mullen R. Orthosomnia: are some patients taking the quantified self too far? J Clin Sleep Med 2017;13(2):351–354. doi:10.5664/jcsm.6472. PMID 27855740.
  2. How common it is Jahrami H, Trabelsi K, Husain W, et al. Prevalence of orthosomnia in a general population sample: a cross-sectional study. Brain Sci 2024;14(11):1123. doi:10.3390/brainsci14111123. PMID 39595886.
  3. Sleep wearables in Canada Dion K, Porteous M, Kendzerska T, et al. Sleep, health care-seeking behaviors, and perceptions associated with the use of sleep wearables in Canada: results from a nationally representative survey. J Med Internet Res 2025;27:e68816. doi:10.2196/68816. PMID 40534180.
  4. Heart alerts and anxiety Rosman L, Lampert R, Zhuo S, et al. Wearable devices, health care use, and psychological well-being in patients with atrial fibrillation. J Am Heart Assoc 2024;13(15):e033750. doi:10.1161/JAHA.123.033750. PMID 39011944. Varma N, Han JK, Passman R, et al. Promises and perils of consumer mobile technologies in cardiovascular care: JACC Scientific Statement. J Am Coll Cardiol 2024;83(5):611–631. doi:10.1016/j.jacc.2023.11.024. PMID 38296406.
  5. Treating insomnia Edinger JD, Arnedt JT, Bertisch SM, et al. Behavioral and psychological treatments for chronic insomnia disorder in adults: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med 2021;17(2):255–262. doi:10.5664/jcsm.8986. PMID 33164742.
  6. Treating health anxiety Lai L, Liu Y, Axelsson E, et al. The comparative effectiveness of psychological interventions for health anxiety: systematic review and a network meta-analysis of randomised controlled trials. Br J Psychiatry 2026:1–10 (published online May 22, 2026). doi:10.1192/bjp.2026.10647. PMID 42169209.
  7. Slow breathing Lehrer et al. 2020. See Chapter 9.
Ch. 14Who Else Reads Your Numbers?7
  1. Data sharing by health apps Grundy Q, Chiu K, Held F, et al. Data sharing practices of medicines related apps and the mobile ecosystem: traffic, content, and network analysis. BMJ 2019;364:l920. doi:10.1136/bmj.l920. PMID 30894349.
  2. HIPAA and consumer devices US Department of Health and Human Services, Office of the National Coordinator for Health IT. Examining Oversight of the Privacy & Security of Health Data Collected by Entities Not Regulated by HIPAA. Report to Congress, July 2016.
  3. Breach notification US Federal Trade Commission. Health Breach Notification Rule; final rule. Federal Register 2024;89:47028 (May 30, 2024); effective July 29, 2024.
  4. EU law Regulation (EU) 2016/679 (General Data Protection Regulation), Articles 4(15) and 9. European Data Protection Board and European Data Protection Supervisor. Joint Opinion 03/2022 on the Proposal for a Regulation on the European Health Data Space. July 12, 2022.
  5. The Flo case Fierce Healthcare. Report on the California jury verdict concerning Flo Health data, August 4, 2025, including the 2021 FTC settlement.
  6. AI coaches Khasentino J, Belyaeva A, Liu X, et al. A personal health large language model for sleep and fitness coaching. Nat Med 2025;31(10):3394–3403. doi:10.1038/s41591-025-03888-0. PMID 40813712.
  7. Wellness devices FDA General Wellness guidance, January 2026. See Chapter 3.
Ch. 15Read Your Device Like a Scientist4
  1. Trackers help people move more Ferguson et al. 2022. See Chapter 6.
  2. Compare with yourself Quer et al. 2020. See Chapter 4.
  3. Accuracy by kind of number Doherty et al. 2024. See Chapter 1.
  4. Home blood pressure Parati et al. 2021. See Chapter 11.
BackWorksheets at the back of the book2
  1. Brand Lookup Feature names checked on October 27, 2026 against official pages of Apple (Apple Health features page), Samsung (Samsung Health page and Samsung Newsroom, 2026), Google (Google Health Help, "What is Morning Brief"), Garmin (Garmin blog pages on health and sleep features), Oura (Oura Member Care help categories) and WHOOP (WHOOP membership page).
  2. Worksheets 1–6 and Choose a Device for the Job Based on the chapters named on each page; the four-week baseline and the device-free week are this book's practical methods, not tested in studies of their own.

Sources for the remaining books are being added.