Research ArticleTools for Practice

Water for weight loss

Danielle Perry and Karenn Chan
Canadian Family Physician July 2022; 68 (7) 519; DOI: https://doi.org/10.46747/cfp.6807519

Clinical question

Does increasing water intake lead to weight loss?

Bottom line

Results of small to moderate size studies with widely variable designs and compliance issues are inconsistent. Replacing caloric beverages with diet beverages (DBs) or water inconsistently improved weight loss; replacing DBs with water produced even less clear results. Preloading water (500 mL) before meals may improve weight loss by 1 to 2 kg over 3 months.

Evidence

Results are from RCTs and statistically different. Baseline body mass index was 31 to 36 kg/m2 (weight 76 to 101 kg).

  • Increasing water.

    • - Two RCTs (240 women and 38 adolescents, respectively, who consumed about 400 calories/d from sugary drinks) comparing counseling with or without advice to drink water found the following after 24 to 36 weeks.1,2

      • — Weight loss: Not different.

      • — One trial provided water (2 to 3 L/d).1 Only 1 in 19 participants achieved target water intake in 1 RCT.2

  • Replacing caloric beverages.

    • - Adherence counseling plus replacing more than 2 caloric beverages with water or DBs vs weight loss advice3 (N=318, consuming about 350 calories/d from sugary drinks) resulted in the following after 6 months.

      • — Weight loss: Not different.

      • — More than 5% weight loss: 20% (water, DBs) vs 11% (advice); NNT=11.

  • Replacing DBs.

    • - Cognitive behavioural therapy with continued DBs or water4,5 (N=303, consuming about 700 mL of beverages daily) resulted in the following after 52 weeks.

      • — Weight loss: 6 kg (DBs) vs 2 kg (water).

      • — Funder: American Beverage Association.

    • - A hypocaloric diet with or without replacing DBs with water6,7 (71 women) resulted in the following after 18 months.

      • — Weight loss: 0.1 kg (diet) vs 1.7 kg (diet, water).

    • - A similar6,7 RCT (81 women) found weight loss of 5.3 kg (diet) vs 6.4 kg (diet, water) after 24 weeks.8

  • “Preloading” water (500 mL, 30 minutes before meals).

    • - A hypocaloric diet with or without water9 (N=48) resulted in the following after 12 weeks.

      • — Weight loss: 7.4 kg (preloaded water) vs 5.5 kg (diet).

    • - An RCT of water vs “imagining being full”10 (N=84) found the following after 12 weeks.

      • — Weight loss: 2.4 kg (preloaded) vs 1.2 kg (imagining).

      • — More than 5% weight loss: 27% (preloaded) vs 5% (imagining), NNT=5.

  • A systematic review found similar results.11

Context

  • Obesity guidelines do not address water intake.12

  • Limitations included compliance issues2 and analyzing the data for only those who completed the study.9

Implementation

Evidence for drinking 8 glasses of water daily comes mainly from a US survey (N=33,000, 1988-1994) that found median total water intake (about 20% from food) to be 3.7 L for men and 2.7 L for women aged 19 to 30.13 Water requirements (eg, activity levels, heat) vary, so a recommendation could not be made for half of apparently healthy adults.14

Notes

Tools for Practice articles in CFP are adapted from peer-reviewed articles at http://www.toolsforpractice.ca and summarize practice-changing medical evidence for primary care. Coordinated by Dr G. Michael Allan and Dr Adrienne J. Lindblad, articles are developed by the Patients, Experience, Evidence, Research (PEER) team and supported by the College of Family Physicians of Canada and its Alberta, Ontario, and Saskatchewan Chapters. Feedback is welcome at toolsforpractice{at}cfpc.ca.

Footnotes

  • Competing interests

    None declared

References

  1. 1.↵
    1. Hernández-Cordero S,
    2. Barquera S,
    3. Rodríquez-Ramírez S,
    4. Villanueva-Borbolla MA,
    5. González de Cossio T,
    6. Rivera Dommarco J, et al.
    Substituting water for sugar-sweetened beverages reduces circulating triglycerides and the prevalence of metabolic syndrome in obese but not in overweight Mexican women in a randomized controlled trial. J Nutr 2014;144(11):1742-52. Epub 2014 Sep 3.
    OpenUrlAbstract/FREE Full Text
  2. 2.↵
    1. Wong JMW,
    2. Ebbeling CB,
    3. Robinson L,
    4. Feldman HA,
    5. Ludwig DS.
    Effects of advice to drink 8 cups of water per day in adolescents with overweight or obesity: a randomized clinical trial. JAMA Pediatr 2017;171(5):e170012. Epub 2017 May 1.
    OpenUrl
  3. 3.↵
    1. Tate DF,
    2. Turner-McGrievy G,
    3. Lyons E,
    4. Stevens J,
    5. Erickson K,
    6. Polzien K, et al.
    Replacing caloric beverages with water or diet beverages for weight loss in adults: main results of the choose healthy options consciously everyday (CHOICE) randomized clinical trial. Am J Clin Nutr 2012;95(3):555-63. Epub 2012 Feb 1. Erratum in: Am J Clin Nutr 2013;98(6):1599.
    OpenUrlAbstract/FREE Full Text
  4. 4.↵
    1. Peters JC,
    2. Wyatt HR,
    3. Foster GD,
    4. Pan Z,
    5. Wojtanowski AC,
    6. Vander Veur SS, et al.
    The effects of water and non-nutritive sweetened beverages on weight loss during a 12-week weight loss treatment program. Obesity (Silver Spring) 2014;22(6):1415-21.
    OpenUrl
  5. 5.↵
    1. Peters JC,
    2. Beck J,
    3. Cardel M,
    4. Wyatt HR,
    5. Foster GD,
    6. Pan Z, et al.
    The effects of water and non-nutritive sweetened beverages on weight loss and weight maintenance: a randomized clinical trial. Obesity (Silver Spring) 2016;24(2):297-304. Epub 2015 Dec 26.
    OpenUrl
  6. 6.↵
    1. Madjd A,
    2. Taylor MA,
    3. Delavari A,
    4. Malekzadeh R,
    5. Macdonald IA,
    6. Farshchi HR.
    Effects on weight loss in adults of replacing diet beverages with water during a hypoenergetic diet: a randomized, 24-wk clinical trial. Am J Clin Nutr 2015;102(6):1305-12. Epub 2015 Nov 4.
    OpenUrlAbstract/FREE Full Text
  7. 7.↵
    1. Madjd A,
    2. Taylor MA,
    3. Delavari A,
    4. Malekzadeh R,
    5. Macdonald IA,
    6. Farshchi HR.
    Effects of replacing diet beverages with water on weight loss and weight maintenance: 18-month follow-up, randomized clinical trial. Int J Obes (Lond) 2018;42(4):835-40. Epub 2017 Dec 21.
    OpenUrl
  8. 8.↵
    1. Madjd A,
    2. Taylor MA,
    3. Delavari A,
    4. Malekzadeh R,
    5. Macdonald IA,
    6. Farshchi HR.
    Beneficial effects of replacing diet beverages with water on type 2 diabetic obese women following a hypo-energetic diet: a randomized, 24-week clinical trial. Diabetes Obes Metab 2017;19(1):125-32. Epub 2016 Oct 16.
    OpenUrl
  9. 9.↵
    1. Dennis EA,
    2. Dengo AL,
    3. Comber DL,
    4. Flack KD,
    5. Savla J,
    6. Davy KP, et al.
    Water consumption increases weight loss during a hypocaloric diet intervention in middle-aged and older adults. Obesity (Silver Spring) 2010;18(2):300-7. Epub 2009 Aug 6.
    OpenUrl
  10. 10.↵
    1. Parretti HM,
    2. Aveyard P,
    3. Blannin A,
    4. Clifford SJ,
    5. Coleman SJ,
    6. Roalfe A, et al.
    Efficacy of water preloading before main meals as a strategy for weight loss in primary care patients with obesity: RCT. Obesity (Silver Spring) 2015;23(9):1785-91. Epub 2015 Aug 3.
    OpenUrl
  11. 11.↵
    1. Bracamontes-Castelo G,
    2. Bacardí-Gascón M,
    3. Jiménez Cruz A.
    Effect of water consumption on weight loss: a systematic review. Nutr Hosp 2019;36(6):1424-9.
    OpenUrl
  12. 12.↵
    1. Wharton S,
    2. Lau DCW,
    3. Vallis M,
    4. Sharma AM,
    5. Biertho L,
    6. Campbell-Scherer D, et al.
    Obesity in adults: a clinical practice guideline. CMAJ 2020;192(4):E875-91.
    OpenUrlFREE Full Text
  13. 13.↵
    Third National Health and Nutrition Examination Survey, 1988–1994. Hyattsville, MD: US Department of Health and Human Services, National Center for Health Statistics; 1994.
  14. 14.↵
    Institute of Medicine. Dietary reference intakes for water, potassium, sodium, chloride, and sulfate. Washington, DC: National Academies Press; 2005.
Back to top

In this issue

Print
Download PDF
Article Alerts
Email Article
Citation Tools
Respond to this article
Water for weight loss
Danielle Perry, Karenn Chan
Canadian Family Physician Jul 2022, 68 (7) 519; DOI: 10.46747/cfp.6807519
Twitter logo Facebook logo Mendeley logo

Jump to section