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LOW CARB DIETS AND WEIGHT LOSS

This section outlines some of the key research findings regarding the effect of low carb diets on weight loss.

 

RESEARCH FINDINGS (see below for references)

a. Low carb diets have been associated with weight loss

 

Compared to high carb diets, low carb diets have been associated with:

b. similar or greater weight loss in various populations including:

b.i. overweight or obese adults, 

b.ii. adults with type 2 diabetes, 

b.iii. adults without type 2 diabetes, 

b.iv. overweight or obese adolescents

c. greater weight loss, despite reports of:

c.i. Similar calorie intakes

c.ii. Greater calorie intakes

d. No difference in weight loss

 

PRACTICAL IMPLICATION: Low carb diets are likely to result in weight loss.

 

Not only have low carb diets been associated with weight loss (a), but often times when compared to a high carb diet, weight loss results are greater when using a low carb diet (b). The observation of greater weight loss compared to high carb diets has been repeated in many different populations (b.i-iv). However, there are also reports of no difference in weight loss between high carb and low carb diets (d). 

 

Of particular interest are the reports of greater weight loss in low carb diets compared to high carb diets despite similar (c.i.) and even sometimes greater (c.ii) calorie intakes. That is, in some studies, people on a low carb diet report similar (c.i.) or even greater (c.ii) calorie intakes compared to people on a high carb diet, and the people in the low carb diet still lose more weight.

This observation might be used to support the following possible claims:

  1. Low carb diets result in weight loss despite smaller calorie deficits. This would contradict the energy balance theory that weight loss is caused by a calorie deficit and nothing more.

  2. Low carb diets result in greater energy expenditure for some reason. That is, people on a low carb diet for some reason become more active than people on a high carb diet. For example, it might be argued that the different diets induce different hormone responses that cause the dieters to become less energetic (on a high carb diet) or more energetic (on a low carb diet), so the low carb diet results in greater energy expediture.

 

Both of these claims would be highly controversial and too firm a claim based on current research. They are mentioned here only to highlight the fact that they do not belong in a sales pitch for a low-carb diet program. They belong in academia to be explored and hopefully proved or disproved. 

 

More reasonable explanations of the observations might include following:

  1. The experiments were somehow flawed in data collection.

  2. People who consume low carb diets are for some reason more motivated to exercise more. For example, a participant put in the low carb group does some of their own research on low carb diets and the fact that they have been associated with weight loss in so many instances. So now the participant is more motivated to be disciplined in diet and exercise.

 

A NOTE ON THE PRACTICAL IMPLICATION

The sentence: “Low carb diets are likely to result in weight loss” is used as opposed to “Low carb diets can be recommended for weight loss”. This is because the mere observation that low carb diets often result in weight loss does not necessarily mean that a low carb diet is safe. That topic is covered elsewhere.

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RESEARCH

 

  1. a. Low carb diets have been associated with weight loss

  • Sacks FM, Bray GA, Carey VJ, et al.: Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. N Engl J Med 2009, 360:859–873. 

  • Westman EC, Yancy WS Jr, Mavropoulos JC, et al.: The effect of a low-carbohydrate, ketogenic diet versus a low glycemic index diet on glycemic control in type 2 diabetes mellitus. Nutr Metab (Lond) 2008, 5:36. 

  • Tay J, Brinkworth GD, Noakes M, et al. Metabolic effects of weight loss on a very-low- carbohydrate diet compared with an isocaloric high-carbohydrate diet in abdominally obese subjects. J Am Coll Cardiol. 2008;51:59-67. 

  • Brehm BJ, Spang SE, Lattin BL, et al. The role of energy expenditure in the differential weight loss in obese women on low-fat and low-carbohydrate diets. J Clin Endocrinol Metab 2005; 90: 1475–1482.

  • Brehm BJ, Seeley RJ, Daniels SR, et al. (2003) A randomized trial comparing a very low carbohydrate diet and a calorie-restricted low fat diet on body weight and cardiovascular risk factors in healthy women. J Clin Endocrinol Metab 88, 1617–1623. 

  • Bueno NB, de Melo IS, de Oliveira SL, et al. (2013) Very- low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomised controlled trials. Br J Nutr 110, 1178–1187. 

  • Samaha FF, Iqbal N, Seshadri P, Chicano KL, Daily DA, et al. (2003) A low-carbohydrate as compared with a low-fat diet in severe obesity. N Engl J Med 348: 2074-2081.

  • Bueno NB, De Melo IS, De Oliveira SL, et al. Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomised controlled trials. Br J Nutr 2013;110:1178–87. 

  • Moyad MA. Fad diets and obesity—Part III: a rapid review of some of the more popular low carbohydrate diets. Urol Nurs 2004;24:442–5.
    Blackburn GL, Phillips JC, Morreale S. Physician’s guide to popular low-carbohydrate weight-loss diets. Cleve Clin J Med 2001;68:761, 765–6, 768–9, 773–4. 

  • Smith SR. A look at the low-carbohydrate diet. N Engl J Med 2009;361:2286–8. 

  • Naude CE, Schoonees A, Senekal M, et al. Low carbohydrate versus isoenergetic  balanced diets for reducing weight and cardiovascular risk: a systematic review  and meta-analysis. PLoS ONE 2014;9:e100652. 

  • 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;312:923–33. 

  • Bueno NB, De Melo IS, De Oliveira SL, et al. Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomised controlled trials. Br J Nutr 2013;110:1178–87. Ajala O, English P, Pinkney J. 

  • Systematic review and meta-analysis of different dietary approaches to the management of type 2 diabetes. Am J Clin Nutr 2013;97:505–16. 

  • Hu T, Mills KT, Yao L, et al. Effects of low-carbohydrate diets versus low-fat diets on metabolic risk factors: a meta-analysis of randomized controlled clinical trials. Am J Epidemiol 2012;176(Suppl 7):S44–54. 

  • Hession M, Rolland C, Kulkarni U, et al. Systematic review of randomized controlled trials of low-carbohydrate vs. low-fat/low-calorie diets in the management of obesity and its comorbidities. Obes Rev 2009;10:36–50. 

  • Nordmann AJ, Nordmann A, Briel M, et al. Effects of low-carbohydrate vs low-fat diets on weight loss and cardiovascular risk factors: a meta-analysis of randomized controlled trials. Arch Intern Med 2006;166:285–93. 

  • Santos FL, Esteves SS, Da Costa PA, et al. Systematic review and meta-analysis of clinical trials of the effects of low carbohydrate diets on cardiovascular risk factors. Obes Rev 2012;13:1048–66. 

  • Tobias DK, Chen M, Manson JE, et al. Effect of low-fat diet interventions versus other diet interventions on long-term weight change in adults: a systematic review and meta-analysis. Lancet Diabetes Endocrinol 2015;3:968–79. 

  • Sackner-Bernstein J, Kanter D, Kaul S. Dietary intervention for overweight and obese adults: comparison of low-carbohydrate and low-fat diets. A meta-analysis.  PLoS ONE 2015;10:e0139817. 

  • Mansoor N, Vinknes KJ, Veierod MB, et al. Effects of low-carbohydrate diets v. low-fat diets on body weight and cardiovascular risk factors: a meta-analysis of randomised controlled trials. Br J Nutr 2016;115:466–79.

  • Gardner CD, Kiazand A, Alhassan S, et al. Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A to Z Weight Loss Study: a randomized trial. JAMA 2007;297:969–77. 

  • Shai I, Schwarzfuchs D, Henkin Y, et al. Weight loss with a low-carbohydrate, Mediterranean, or low-fat diet. N Engl J Med 2008;359:229–41.

  • Krebs NF, Gao D, Gralla J, et al. Efficacy and safety of a high protein, low carbohydrate diet for weight loss in severely obese adolescents. J Pediatr 2010;157:252–8. 

  • Sondike SB, Copperman N, Jacobson MS. Effects of a low-carbohydrate diet on weight loss and cardiovascular risk factor in overweight adolescents. J Pediatr 2003;142:253–8. 

  • Partsalaki I, Karvela A, Spiliotis BE. Metabolic impact of a ketogenic diet compared to a hypocaloric diet in obese children and adolescents. J Pediatr Endocrinol Metab 2012;25:697–704. 

  • Daly ME, Paisey R, Paisey R, et al. Short-term effects of severe dietary carbohydrate-restriction advice in Type 2 diabetes—a randomized controlled trial. Diabet Med 2006;23:15–20. 

  • Dyson PA, Beatty S, Matthews DR. A low-carbohydrate diet is more effective in reducing body weight than healthy eating in both diabetic and non-diabetic subjects. Diabet Med 2007;24:1430–5.

  • Saslow LR, Kim S, Daubenmier JJ, et al. A randomized pilot trial of a moderate carbohydrate diet compared to a very low carbohydrate diet in overweight or obese individuals with type 2 diabetes mellitus or prediabetes. PLoS ONE 2014;9: e91027. 

  • Aude YW, Agatston AS, Lopez-Jimenez F, et al. The national cholesterol education program diet vs a diet lower in carbohydrates and higher in protein and monounsaturated fat: a randomized trial. Arch Intern Med 2004;164:2141–6. 

  • Brehm BJ, Seeley RJ, Daniels SR, et al. A randomized trial comparing a very low carbohydrate diet and a calorie-restricted low fat diet on body weight and cardiovascular risk factors in healthy women. J Clin Endocrinol Metab 2003;88:1617–23. 

  • Foster GD, Wyatt HR, Hill JO, et al. A randomized trial of a low-carbohydrate diet for obesity. N Engl J Med 2003;348:2082–90.
    Halyburton AK, Brinkworth GD, Wilson CJ, et al. Low- and high-carbohydrate weight-loss diets have similar effects on mood but not cognitive performance. Am J Clin Nutr 2007;86:580–7. 

  • Nickols-Richardson SM, Coleman MD, Volpe JJ, et al. Perceived hunger is lower and weight loss is greater in overweight premenopausal women consuming a low-carbohydrate/high-protein vs high-carbohydrate/low-fat diet. J Am Diet Assoc 2005;105:1433–7. 

  • Yancy WS Jr, Olsen MK, Guyton JR, et al. A low-carbohydrate, ketogenic diet versus a low-fat diet to treat obesity and hyperlipidemia: a randomized, controlled trial. Ann Intern Med 2004;140:769–77 

  • Volek JS, Phinney SD, Forsythe CE, et al. Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet. Lipids 2009;44:297–309. 

  • Sondike SB, Copperman N, Jacobson MS. Effects of a low-carbohydrate diet on
    weight loss and cardiovascular risk factor in overweight adolescents. J Pediatr
    2003;142:253–8. 

  • Krieger JW, Sitren HS, Daniels MJ, Langkamp-Henken B: Effects of variation in protein and carbohydrate intake on body mass and composition during energy restriction: a meta- regression 1. Am J Clin Nutr 2006, 83:260–274.

 

b.i. Compared to high carb diets, low carb diets have been associated with similar or greater weight loss in overweight or obese adults

  • Westman EC, Yancy WS Jr, Mavropoulos JC, et al.: The effect of a low-carbohydrate, ketogenic diet versus a low glycemic index diet on glycemic control in type 2 diabetes mellitus. Nutr Metab (Lond) 2008, 5:36.

  • Bueno NB, De Melo IS, De Oliveira SL, et al. Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomised controlled trials. Br J Nutr 2013;110:1178–87. 

  • Moyad MA. Fad diets and obesity—Part III: a rapid review of some of the more popular low carbohydrate diets. Urol Nurs 2004;24:442–5.
    Blackburn GL, Phillips JC, Morreale S. Physician’s guide to popular low-carbohydrate weight-loss diets. Cleve Clin J Med 2001;68:761, 765–6, 768–9, 773–4. 

  • Smith SR. A look at the low-carbohydrate diet. N Engl J Med 2009;361:2286–8. 

  • Naude CE, Schoonees A, Senekal M, et al. Low carbohydrate versus isoenergetic  balanced diets for reducing weight and cardiovascular risk: a systematic review  and meta-analysis. PLoS ONE 2014;9:e100652. 

  • 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;312:923–33. 

  • Bueno NB, De Melo IS, De Oliveira SL, et al. Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomised controlled trials. Br J Nutr 2013;110:1178–87. Ajala O, English P, Pinkney J. 

  • Systematic review and meta-analysis of different dietary approaches to the management of type 2 diabetes. Am J Clin Nutr 2013;97:505–16. 

  • Hu T, Mills KT, Yao L, et al. Effects of low-carbohydrate diets versus low-fat diets on metabolic risk factors: a meta-analysis of randomized controlled clinical trials. Am J Epidemiol 2012;176(Suppl 7):S44–54. 

  • Hession M, Rolland C, Kulkarni U, et al. Systematic review of randomized controlled trials of low-carbohydrate vs. low-fat/low-calorie diets in the management of obesity and its comorbidities. Obes Rev 2009;10:36–50. 

  • Nordmann AJ, Nordmann A, Briel M, et al. Effects of low-carbohydrate vs low-fat diets on weight loss and cardiovascular risk factors: a meta-analysis of randomized controlled trials. Arch Intern Med 2006;166:285–93. 

  • Santos FL, Esteves SS, Da Costa PA, et al. Systematic review and meta-analysis of clinical trials of the effects of low carbohydrate diets on cardiovascular risk factors. Obes Rev 2012;13:1048–66. 

  • Tobias DK, Chen M, Manson JE, et al. Effect of low-fat diet interventions versus other diet interventions on long-term weight change in adults: a systematic review and meta-analysis. Lancet Diabetes Endocrinol 2015;3:968–79. 

  • Sackner-Bernstein J, Kanter D, Kaul S. Dietary intervention for overweight and obese adults: comparison of low-carbohydrate and low-fat diets. A meta-analysis.  PLoS ONE 2015;10:e0139817. 

  • Mansoor N, Vinknes KJ, Veierod MB, et al. Effects of low-carbohydrate diets v. low-fat diets on body weight and cardiovascular risk factors: a meta-analysis of randomised controlled trials. Br J Nutr 2016;115:466–79.

  • Gardner CD, Kiazand A, Alhassan S, et al. Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A to Z Weight Loss Study: a randomized trial. JAMA 2007;297:969–77. 

  • Shai I, Schwarzfuchs D, Henkin Y, et al. Weight loss with a low-carbohydrate, Mediterranean, or low-fat diet. N Engl J Med 2008;359:229–41.

  • Tay J, Brinkworth GD, Noakes M, et al. Metabolic effects of weight loss on a very-low- carbohydrate diet compared with an isocaloric high-carbohydrate diet in abdominally obese subjects. J Am Coll Cardiol. 2008;51:59-67.

 

b.ii. Compared to high carb diets, low carb diets have been associated with similar or greater weight loss in adults with type 2 diabetes

  • Daly ME, Paisey R, Paisey R, et al. Short-term effects of severe dietary carbohydrate-restriction advice in Type 2 diabetes—a randomized controlled trial. Diabet Med 2006;23:15–20. 

  • Dyson PA, Beatty S, Matthews DR. A low-carbohydrate diet is more effective in reducing body weight than healthy eating in both diabetic and non-diabetic subjects. Diabet Med 2007;24:1430–5.

  • Saslow LR, Kim S, Daubenmier JJ, et al. A randomized pilot trial of a moderate carbohydrate diet compared to a very low carbohydrate diet in overweight or obese individuals with type 2 diabetes mellitus or prediabetes. PLoS ONE 2014;9: e91027. 

  • Westman EC, Yancy WS Jr, Mavropoulos JC, et al.: The effect of a low-carbohydrate, ketogenic diet versus a low glycemic index diet on glycemic control in type 2 diabetes mellitus. Nutr Metab (Lond) 2008, 5:36.

 

 

b.iii. Compared to high carb diets, low carb diets have been associated with similar or greater weight loss in adults without type 2 diabetes

  • Aude YW, Agatston AS, Lopez-Jimenez F, et al. The national cholesterol education program diet vs a diet lower in carbohydrates and higher in protein and monounsaturated fat: a randomized trial. Arch Intern Med 2004;164:2141–6. 

  • Brehm BJ, Seeley RJ, Daniels SR, et al. A randomized trial comparing a very low carbohydrate diet and a calorie-restricted low fat diet on body weight and cardiovascular risk factors in healthy women. J Clin Endocrinol Metab 2003;88:1617–23. 

  • Foster GD, Wyatt HR, Hill JO, et al. A randomized trial of a low-carbohydrate diet for obesity. N Engl J Med 2003;348:2082–90.
    Halyburton AK, Brinkworth GD, Wilson CJ, et al. Low- and high-carbohydrate weight-loss diets have similar effects on mood but not cognitive performance. Am J Clin Nutr 2007;86:580–7. 

  • Nickols-Richardson SM, Coleman MD, Volpe JJ, et al. Perceived hunger is lower and weight loss is greater in overweight premenopausal women consuming a low-carbohydrate/high-protein vs high-carbohydrate/low-fat diet. J Am Diet Assoc 2005;105:1433–7. 

  • Yancy WS Jr, Olsen MK, Guyton JR, et al. A low-carbohydrate, ketogenic diet versus a low-fat diet to treat obesity and hyperlipidemia: a randomized, controlled trial. Ann Intern Med 2004;140:769–77 

 

b.iv. Compared to high carb diets, low carb diets have been associated with similar or greater weight loss in overweight or obese adolescents

  • Krebs NF, Gao D, Gralla J, et al. Efficacy and safety of a high protein, low carbohydrate diet for weight loss in severely obese adolescents. J Pediatr 2010;157:252–8. 

  • Sondike SB, Copperman N, Jacobson MS. Effects of a low-carbohydrate diet on weight loss and cardiovascular risk factor in overweight adolescents. J Pediatr 2003;142:253–8. 

  • Partsalaki I, Karvela A, Spiliotis BE. Metabolic impact of a ketogenic diet compared to a hypocaloric diet in obese children and adolescents. J Pediatr Endocrinol Metab 2012;25:697–704.

 

c.i. Compared to high carb diets, low carb diets have been associated with greater weight loss, despite reports of similar calorie intakes.

  • Naude CE, Schoonees A, Senekal M, et al. Low carbohydrate versus isoenergetic
    balanced diets for reducing weight and cardiovascular risk: a systematic review
    and meta-analysis. PLoS ONE 2014;9:e100652. 

  • Krieger JW, Sitren HS, Daniels MJ, et al. Effects of variation in protein and carbohydrate intake on body mass and composition during energy restriction: a meta-regression 1. Am J Clin Nutr 2006;83:260–74. 

  • Gardner CD, Kiazand A, Alhassan S, et al. Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women—the A to Z Weight Loss Study: a randomized trial. JAMA. 2007;297:969-977

 

c.ii. Compared to high carb diets, low carb diets have been associated with greater weight loss, despite reports of greater calorie intakes in the low carb diet group.

  • Volek JS, Phinney SD, Forsythe CE, et al. Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet. Lipids 2009;44:297–309. 

  • Sondike SB, Copperman N, Jacobson MS. Effects of a low-carbohydrate diet on weight loss and cardiovascular risk factor in overweight adolescents. J Pediatr 2003;142:253–8. 

  • Volek JS, Sharman MJ, Gomez AL, et al. Comparison of a very low-carbohydrate and low-fat diet on fasting lipids, LDL subclasses, insulin resistance, and postprandial lipemic responses in overweight women. J Am Coll Nutr 2004;23:177–84. 

  • Brehm BJ, Seeley RJ, Daniels SR, et al. A randomized trial comparing a very low carbohydrate diet and a calorie-restricted low fat diet on body weight and cardiovascular risk factors in healthy women. J Clin Endocrinol Metab 2003;88:1617–23. 

  • Greene (17lb LF compared to 23lb LC) 

  • Westman EC, Yancy WS Jr, Mavropoulos JC, et al.: The effect of a low-carbohydrate, ketogenic diet versus a low glycemic index diet on glycemic control in type 2 diabetes mellitus. Nutr Metab (Lond) 2008, 5:36. 

 

 

 

d. Compared to high carb diets, low carb diets have also been associated with no significant difference in weight loss.

  • Naude CE, Schoonees A, Senekal M, et al. Low carbohydrate versus isoenergetic balanced diets for reducing weight and cardiovascular risk: a systematic review and meta-analysis. PLoS ONE 2014;9:e100652. 

  • 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;312:923–33. 

  • Hu T, Mills KT, Yao L, et al. Effects of low-carbohydrate diets versus low-fat diets on metabolic risk factors: a meta-analysis of randomized controlled clinical trials. Am J Epidemiol 2012;176(Suppl 7):S44–54.

  • Tay J, Luscombe-Marsh ND, Thompson CH, et al. Comparison of low- and high-carbohydrate diets for type 2 diabetes management: a randomized trial. Am J Clin Nutr 2015;102:780–90. 

  • Snorgaard O, Poulsen GM, Andersen HK, et al. Systematic review and meta-analysis of dietary carbohydrate restriction in patients with type 2 diabetes. BMJ Open Diabetes Research and Care 2017;5: e000354. doi:10.1136/ bmjdrc-2016-000354

  • van Wyk HJ, Davis RE, Davies JS. A critical review of low-carbohydrate diets in people with type 2 diabetes. Diabet Med 2016;33:148–57. 

 

 

FULL REVIEWS

  • Westman et al (2003) A review of low-carbohydrate ketogenic diets. Curr Atheroscler Rep. Nov;5(6):476-83.

  • Noakes TD, Windt J. Br J Sports Med 2016;51:133–139. Evidence that supports the prescription of low-carbohydrate high-fat diets: a narrative review

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