Science.

High-quality evidence from scientific studies supports the use of low carb diets for weight loss and medical conditions including type 2 diabetes and high blood pressure. The lists below link to some of the most relevant studies.

For science relevant to the menopause, peri-menopause and use of HRT please click here.

Weight loss.

Low carb diets are effective for weight loss

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 Oct 20;10(10):e0139817. doi: 10.1371/journal.pone.0139817. PMID: 26485706; PMCID: PMC4618935.

Mansoor N, Vinknes KJ, Veierød MB, Retterstøl K. 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 Feb 14;115(3):466-79. doi: 10.1017/S0007114515004699. PMID: 26768850.

Low carb diets result in more fat loss (not just weight loss)

Hashimoto Y, Fukuda T, Oyabu C, Tanaka M, Asano M, Yamazaki M, Fukui M. Impact of low-carbohydrate diet on body composition: meta-analysis of randomized controlled studies. Obes Rev. 2016 Jun;17(6):499-509. doi: 10.1111/obr.12405. Epub 2016 Apr 5. PMID: 27059106.

Low carb diets reduce weight and improve major risk factors for heart disease.

Santos FL, Esteves SS, da Costa Pereira A, Yancy WS Jr, Nunes JP. Systematic review and meta-analysis of clinical trials of the effects of low carbohydrate diets on cardiovascular risk factors. Obes Rev. 2012 Nov;13(11):1048-66. doi: 10.1111/j.1467-789X.2012.01021.x. Epub 2012 Aug 21. PMID: 22905670.

Rising insulin inceases body fat, even when calories stay the same.

Torbay N, Bracco EF, Geliebter A, Stewart IM, Hashim SA. Insulin increases body fat despite control of food intake and physical activity. Am J Physiol. 1985 Jan;248(1 Pt 2):R120-4. doi: 10.1152/ajpregu.1985.248.1.R120. PMID: 3881983.

Eating a low carb breakfast reduced hunger and calories consumed at lunch (compaired to a breakfast of the same calories in carbs).

Vander Wal JS, Marth JM, Khosla P, Jen KL, Dhurandhar NV. Short-term effect of eggs on satiety in overweight and obese subjects. J Am Coll Nutr. 2005 Dec;24(6):510-5. doi: 10.1080/07315724.2005.10719497. PMID: 16373948.

Low-carb diets are better than other diets at preventing weight regain after loss.

Hron BM, Ebbeling CB, Feldman HA, Ludwig DS. Relationship of insulin dynamics to body composition and resting energy expenditure following weight loss. Obesity (Silver Spring). 2015 Nov;23(11):2216-22. doi: 10.1002/oby.21213. Epub 2015 Sep 16. PMID: 26373701; PMCID: PMC4633340.

Type 2 diabetes

Low carb diets improve blood sugar control

Sainsbury E, Kizirian NV, Partridge SR, Gill T, Colagiuri S, Gibson AA. Effect of dietary carbohydrate restriction on glycemic control in adults with diabetes: A systematic review and meta-analysis. Diabetes Res Clin Pract. 2018 May;139:239-252. doi: 10.1016/j.diabres.2018.02.026. Epub 2018 Mar 6. PMID: 29522789.

Insulin therapy increases weight gain and (in type 2 DM).

Henry RR, Gumbiner B, Ditzler T, Wallace P, Lyon R, Glauber HS. Intensive conventional insulin therapy for type II diabetes. Metabolic effects during a 6-mo outpatient trial. Diabetes Care. 1993 Jan;16(1):21-31. doi: 10.2337/diacare.16.1.21. PMID: 8422777.

ADVANCE Collaborative Group, Patel A, MacMahon S, Chalmers J, Neal B, Billot L, Woodward M, Marre M, Cooper M, Glasziou P, Grobbee D, Hamet P, Harrap S, Heller S, Liu L, Mancia G, Mogensen CE, Pan C, Poulter N, Rodgers A, Williams B, Bompoint S, de Galan BE, Joshi R, Travert F. Intensive blood glucose control and vascular outcomes in patients with type 2 diabetes. N Engl J Med. 2008 Jun 12;358(24):2560-72. doi: 10.1056/NEJMoa0802987. Epub 2008 Jun 6. PMID: 18539916. 

The benefits of a low carb diet in diabetes

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

Diabetes Research and Clinical Practice 2018: Effect of dietary carbohydrate restriction on glycemic control in adults with diabetes: A systematic review and meta-analysis

BMJ Open Diabetes Research and Care 2017: Systematic review and meta-analysis of dietary carbohydrate restriction in patients with type 2 diabetes

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

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

Low carb diets reduce the need for medication and improve health markers (HbA1c, HDL, TG, and blood pressure) in type 2 diabetes.

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

High blood pressure.

Almost all people with hypertension are Insulin Resistent

Goff DC Jr, Zaccaro DJ, Haffner SM, Saad MF; Insulin Resistance Atherosclerosis Study. Insulin sensitivity and the risk of incident hypertension: insights from the Insulin Resistance Atherosclerosis Study. Diabetes Care. 2003 Mar;26(3):805-9. doi: 10.2337/diacare.26.3.805. PMID: 12610041.

High insulin and Insulin Resistence work together chronically increase BP

DeFronzo RA, Ferrannini E. Insulin resistance. A multifaceted syndrome responsible for NIDDM, obesity, hypertension, dyslipidemia, and atherosclerotic cardiovascular disease. Diabetes Care. 1991 Mar;14(3):173-94. doi: 10.2337/diacare.14.3.173. PMID: 2044434.

Sugar increases blood pressure more than salt

DiNicolantonio JJ, O'Keefe JH, Lucan SC. An unsavory truth: sugar, more than salt, predisposes to hypertension and chronic disease. Am J Cardiol. 2014 Oct 1;114(7):1126-8. doi: 10.1016/j.amjcard.2014.07.002. Epub 2014 Jul 14. PMID: 25212553.

Dietary fat does not increase blood pressure

Chiu S, Bergeron N, Williams PT, Bray GA, Sutherland B, Krauss RM. Comparison of the DASH (Dietary Approaches to Stop Hypertension) diet and a higher-fat DASH diet on blood pressure and lipids and lipoproteins: a randomized controlled trial. Am J Clin Nutr. 2016 Feb;103(2):341-7. doi: 10.3945/ajcn.115.123281. Epub 2015 Dec 30. PMID: 26718414; PMCID: PMC4733264.

Lack of evidence that reducing salt in food affects the risk of heart disease or death.

Cochrane reviews 2011: Reduced dietary salt for the prevention of cardiovascular disease

Low-carb diets led to a decrease in systolic BP.

PLoS One 2020: The effects of low-carbohydrate diets on cardiovascular risk factors: A meta-analysis

Low carb diets improve systolic BP more than low fat diets.

PLoS One 2015: Dietary Intervention for Overweight and Obese Adults: Comparison of Low-Carbohydrate and Low-Fat Diets. A Meta-Analysis

Obesity Reviews 2009: Systematic review of randomized controlled trials of low-carbohydrate vs. low-fat/low-calorie diets in the management of obesity and its comorbidities

High Cholesterol.

Increased risk of CVD with small, dense LDL.

Lamarche B, Tchernof A, Moorjani S, Cantin B, Dagenais GR, Lupien PJ, Després JP. Small, dense low-density lipoprotein particles as a predictor of the risk of ischemic heart disease in men. Prospective results from the Québec Cardiovascular Study. Circulation. 1997 Jan 7;95(1):69-75. doi: 10.1161/01.cir.95.1.69. PMID: 8994419.

HDL/TG ratio as an estimate of LDL particle size

Maruyama C, Imamura K, Teramoto T. Assessment of LDL particle size by triglyceride/HDL-cholesterol ratio in non-diabetic, healthy subjects without prominent hyperlipidemia. J Atheroscler Thromb. 2003;10(3):186-91. doi: 10.5551/jat.10.186. PMID: 14564088.

Insulin reistence is a risk factor for atherosclerosis

Circulation. 2000: Insulin-resistant prediabetic subjects have more atherogenic risk factors than insulin-sensitive prediabetic subjects: implications for preventing coronary heart disease during the prediabetic state.

Dietary cholesterol and cardiovascular risk

Curr Opin Clin Nutr Metab Care. 2012: Rethinking dietary cholesterol.

Am J Clin Nutr. 2015: Dietary cholesterol and cardiovascular disease: a systematic review and meta-analysis.

Eating cholesterol reduces cholesterol synthesis

Arterioscler Thromb Vasc Biol. 1996: Dietary cholesterol feeding suppresses human cholesterol synthesis measured by deuterium incorporation and urinary mevalonic acid levels.

Low-carb diets increase HDL and lower TG.

PLoS One 2020: The effects of low-carbohydrate diets on cardiovascular risk factors: A meta-analysis

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

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

Low-carb diets better for TG and HDL, compared to low fat.

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

PLoS One 2015: Dietary Intervention for Overweight and Obese Adults: Comparison of Low-Carbohydrate and Low-Fat Diets. A Meta-Analysis

Obesity Reviews 2009: Systematic review of randomized controlled trials of low-carbohydrate vs. low-fat/low-calorie diets in the management of obesity and its comorbidities

Archives of Internal Medicine 2006: Effects of low-carbohydrate vs low-fat diets on weight loss and cardiovascular risk factors: a meta-analysis of randomized controlled trials

 PCOS

Women with PCOS have marked insulin resistance, independent of weight.

Endocrine Reviews: Insulin Resistance and the Polycystic Ovary Syndrome Revisited: An Update on Mechanisms and Implications

Diabetes 1989: Profound peripheral insulin resistance, independent of obesity, in polycystic ovary syndrome.

Reducing insulin and improving insulin sensitivity increases natural ovulation

Velazquez EM, Mendoza S, Hamer T, Sosa F, Glueck CJ. Metformin therapy in polycystic ovary syndrome reduces hyperinsulinemia, insulin resistance, hyperandrogenemia, and systolic blood pressure, while facilitating normal menses and pregnancy. Metabolism. 1994 May;43(5):647-54. doi: 10.1016/0026-0495(94)90209-7. PMID: 8177055.

Low carb diets improve PCOS

Preliminary data supports the use of low carb diets in PCOS. Hopefully we will see some long term, high quality studies in the future.

Nutr Metab (Lond). 2005 The effects of a low-carbohydrate, ketogenic diet on the polycystic ovary syndrome: a pilot study.

Journal of Obesity & Weight Loss Therapy 2015: Low-starch/low-dairy diet results in successful treatment of obesity and co-morbidities linked to polycystic ovary syndrome (PCOS)

Journal of Translational Medicine 2020: Effects of a ketogenic diet in overweight women with polycystic ovary syndrome 

Fertility & Sterility 2006: Role of diet in the treatment of polycystic ovary syndrome

Clinical Endocrinology 2013: Favourable metabolic effects of a eucaloric lower‐carbohydrate diet in women with PCOS

Nutrients 2017: The effect of low-carbohydrate diets on fertility hormones and outcomes in overweight and obese women: a systematic review [systematic review of randomized and nonrandomized trials; weak evidence]