The page below summarizes the core scientific evidence behind low-carb and keto diets. Although these diets are still considered somewhat controversial by some health professionals, there is now high-quality evidence to support their routine use for weight loss and certain metabolic conditions, such as type 2 diabetes, high blood pressure, and some forms of dyslipidemia.
PLoS One 2015: Dietary intervention for overweight and obese adults: Comparison of low-carbohydrate and low-fat diets. A meta-analysis [strong evidence] Learn more
The British Journal of Nutrition 2016: Effects of low-carbohydrate diets v. low-fat diets on body weight and cardiovascular risk factors: a meta-analysis of randomised controlled trials [strong evidence] Learn more
Obesity Reviews 2016: Impact of low-carbohydrate diet on body composition: meta-analysis of randomized controlled studies [strong evidence]
The Lancet 2015: Effect of low-fat diet interventions versus other diet interventions on long-term weight change in adults: a systematic review and meta-analysis [strong evidence]
Obesity Reviews 2012: Systematic review and meta-analysis of clinical trials of the effects of low carbohydrate diets on cardiovascular risk factors [strong evidence]
Here are links to all the studies above, ordered from oldest to newest:
Brehm -03, Foster -03, Samaha -03, Sondike -03, Aude -04, Volek -04, Meckling -04, Yancy -04, Stern -04, McAuley -05, Nickols-R -05, Dansinger -05, Daly -06, Truby -06, Gardner -07, Ebbeling -07, Halyburton -07, Dyson -07, Westman -08, Keogh -08, Shai -08, Tay -08, Davis -09, Bradley -09, Volek -09, Sacks -09, Brinkworth -09, Jenkins -09, Frisch -09, Elhayany -10, Iqbal -10, Lim -10, Hernandez -10, Yancy -10, Foster -10, Krebs -10, Goldstein -11, Summer -11, Guldbrand -12, Partsalaki -12, Ruth -13, Yamada -14, Saslow -14, Bazzano -14, Tay -15, Saslow -17, Gardner -18.
Links to the meta-analyses:
Nordmann -06, Hession -08, Sackner-B -15, Tobias -15, Mansoor -16.
Nutrition Reviews 2019: Effects of carbohydrate-restricted diets on low-density lipoprotein cholesterol levels in overweight and obese adults: a systematic review and meta-analysis [strong evidence]
Archives of Internal Medicine 2009: A systematic review of the evidence supporting a causal link between dietary factors and coronary heart disease [moderate evidence]
The American Journal of Clinical Nutrition 2010: Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease [moderate evidence]
British Medical Journal 2015: Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: systematic review and meta-analysis of observational studies [moderate evidence]
British Journal of Sports Medicine 2017: Evidence from prospective cohort studies does not support current dietary fat guidelines: a systematic review and meta-analysis [moderate evidence]
Cochrane Database of Systemic Reviews 2020: Reduction in saturated fat intake for cardiovascular disease [systematic review of randomized trials; strong evidence]
Cochrane Database of Systematic Reviews 2011: Reduced or modified dietary fat for preventing cardiovascular disease [strong evidence]
PloS Med 2010: Effects on coronary heart disease of increasing polyunsaturated fat in place of saturated fat: a systematic review and meta-analysis of randomized controlled trials [strong evidence]
Nutrition Journal 2017: The effect of replacing saturated fat with mostly n-6 polyunsaturated fat on coronary heart disease: a meta-anlysis of randomised controlled trials [strong evidence]
Open Heart 2016: Evidence from randomised controlled trials does not support current dietary fat guidelines: a systematic review and meta-analysis [strong evidence]
Annals of Internal Medicine 2014: Association of dietary, circulating, and supplement fatty acids with coronary risk: a systematic review and meta-analysis [strong evidence]
British Medical Journal 2013: Dietary fatty acids in the secondary prevention of coronary heart disease: a systematic review, meta-analysis and meta-regression [strong evidence]
European Journal of Nutrition 2012: The relationship between high-fat dairy consumption and obesity, cardiovascular, and metabolic disease [weak evidence]
The Lancet 2017: Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study [very weak evidence]
British Medical Journal 2013: Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis [strong evidence]
BMJ 2016: Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968-73) [strong evidence]
The Lancet 2017: Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study [weak evidence]
Circulation 2010: Dietary intervention to reverse carotid atherosclerosis [moderate evidence]
Endocrine, Metabolic & Immune Disorders Drug Targets 2020: Effects of a low carb diet and whey proteins on anthropometric, hematochemical and cardiovascular parameters in subjects with obesity. [non-randomized, weak evidence]
Nutrients 2020: Impact of a ketogenic diet on metabolic parameters in patients with obesity or overweight and with or without type 2 diabetes: A meta-analysis of randomized controlled trials/strong> [systematic review of randomized trials; strong evidence]
Diabetes Research and Clinical Practice 2018: Effect of dietary carbohydrate restriction on glycemic control in adults with diabetes: A systematic review and meta-analysis [strong evidence]
BMJ Open Diabetes Research and Care 2017: Systematic review and meta-analysis of dietary carbohydrate restriction in patients with type 2 diabetes [strong evidence]
The American Journal of Clinical Nutrition 2018: Effects of low-carbohydrate- compared with low-fat-diet interventions on metabolic control in people with type 2 diabetes: a systematic review including GRADE assessments [strong evidence]
Diabetes, Obesity & Metabolism 2019: An evidence‐based approach to developing low‐carbohydrate diets for type 2 diabetes management: a systematic review of interventions and methods [strong evidence]
European Journal of Clinical Nutrition 2017: The interpretation and effect of a low-carbohydrate diet in the management of type 2 diabetes: a systematic review and meta-analysis of randomised controlled trials [strong evidence]
Nutrition 2015: Dietary carbohydrate restriction as the first approach in diabetes management: critical review and evidence base [overview article]
Nutrients 2018: The effect of low-carbohydrate diet on glycemic control in patients with type 2 diabetes [moderate evidence]
Nutrition & Diabetes 2017: Twelve-month outcomes of a randomized trial of a moderate-carbohydrate versus very low-carbohydrate diet in overweight adults with type 2 diabetes mellitus or prediabetes [moderate evidence]
Diabetes Care 2014: A very low-carbohydrate, low–saturated fat diet for type 2 diabetes management: a randomized trial [moderate evidence]
Nutrition & Metabolism 2008: The effect of a low-carbohydrate, ketogenic diet versus a low-glycemic index diet on glycemic control in type 2 diabetes mellitus [moderate evidence]
Diabetic Medicine 2004: Short-term effects of severe dietary carbohydrate-restriction advice in type 2 diabetes–a randomized controlled trial [moderate evidence]
Diabetes Therapy 2018: Effectiveness and safety of a novel care model for the management of type 2 diabetes at 1 year: an open-label, non-randomized, controlled study [weak evidence]
Frontiers in Endocrinology 2019: Long-term effects of a novel continuous remote care intervention including nutritional ketosis for the management of type 2 diabetes: A 2-year non-randomized clinical trial [weak evidence]
Nutrition & Metabolism 2008: Low-carbohydrate diet in type 2 diabetes: stable improvement of bodyweight and glycemic control during 44 months follow-up [weak evidence]
Nutrition 2012: Effect of low-calorie versus low-carbohydrate ketogenic diet in type 2 diabetes [weak evidence]
Nutrients 2018: The effect of low-carbohydrate diet on glycemic control in patients with type 2 diabetes [moderate evidence]
Nutrition & Diabetes 2017: Twelve-month outcomes of a randomized trial of a moderate-carbohydrate versus very low-carbohydrate diet in overweight adults with type 2 diabetes mellitus or prediabetes [moderate evidence]
Diabetes Care 2014: A very low-carbohydrate, low–saturated fat diet for type 2 diabetes management: a randomized trial [moderate evidence]
Nutrition & Metabolism 2008: The effect of a low-carbohydrate, ketogenic diet versus a low-glycemic index diet on glycemic control in type 2 diabetes mellitus [moderate evidence]
Diabetic Medicine 2004: Short-term effects of severe dietary carbohydrate-restriction advice in type 2 diabetes–a randomized controlled trial [moderate evidence]
Diabetes Therapy 2018: Effectiveness and safety of a novel care model for the management of type 2 diabetes at 1 year: an open-label, non-randomized, controlled study [weak evidence]
Frontiers in Endocrinology 2019: Long-term effects of a novel continuous remote care intervention including nutritional ketosis for the management of type 2 diabetes: A 2-year non-randomized clinical trial [weak evidence]
Nutrition & Metabolism 2008: Low-carbohydrate diet in type 2 diabetes: stable improvement of bodyweight and glycemic control during 44 months follow-up [weak evidence]
Nutrition 2012: Effect of low-calorie versus low-carbohydrate ketogenic diet in type 2 diabetes [weak evidence]
Diabetes, Obesity and Metabolism 2019: Low versus high carbohydrate diet in type 1 diabetes: a 12-week randomized open-label crossover study [moderate evidence]
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Diabetes, Obesity and Metabolism 2017: Short-term effects of a low-carbohydrate diet on glycaemic variables and cardiovascular risk markers in patients with type 1 diabetes: a randomized open-label crossover trial [moderate evidence]
Asia Pacific Journal of Clinical Nutrition 2016: A randomised trial of the feasibility of a low-carbohydrate diet vs standard carbohydrate counting in adults with type 1 diabetes taking body weight into account [moderate evidence]
Pediatrics 2018: Management of type 1 diabetes with a very low–carbohydrate diet [weak evidence]
Upsala Journal of Medical Sciences 2005: A low-carbohydrate diet in type 1 diabetes: clinical experience – a brief report [weak evidence]
Diabetology & Metabolic Syndrome 2012: Low-carbohydrate diet in type 1 diabetes, long-term improvement and adherence: a clinical audit [weak evidence]
Pediatrics 2018: Management of type 1 diabetes with a very low–carbohydrate diet [weak evidence]
Upsala Journal of Medical Sciences 2005: A low-carbohydrate diet in type 1 diabetes: clinical experience – a brief report [weak evidence]
Diabetology & Metabolic Syndrome 2012: Low-carbohydrate diet in type 1 diabetes, long-term improvement and adherence: a clinical audit [weak evidence]
Osteoporosis International 2018: Benefits and safety of dietary protein for bone health – an expert consensus paper [overview article]
The American Journal of Clinical Nutrition 2017: Dietary protein and bone health: a systematic review and meta-analysis from the National Osteoporosis Foundation [moderate evidence]
Nutrition 2016: Long-term effects of a very-low-carbohydrate weight-loss diet and an isocaloric low-fat diet on bone health in obese adults [moderate evidence]
Annals of Internal Medicine 2010: Weight and metabolic outcomes after 2 years on a low-carbohydrate versus low-fat diet: a randomized trial [moderate evidence]
The Journal of Pediatrics 2010: Efficacy and safety of a high protein, low carbohydrate diet for weight loss in severely obese adolescents [moderate evidence]
Epilepsia Open 2018: Ketogenic diet for treatment of intractable epilepsy in adults: A meta-analysis of observational studies [weak evidence]
Epilepsia 2018: Effect of modified Atkins diet in adults with drug-resistant focal epilepsy: a randomized controlled trial [moderate evidence]
Acta Neurologica Scandinavica 2017: A randomized controlled trial of the ketogenic diet in refracatory childhood epilepsy [moderate evidence]
Epilepsy Research 2016: Evaluation of a simplified modified Atkins diet for use by parents with low levels of literacy in children with refractory epilepsy: a randomized controlled trial [moderate evidence]