A low-carb diet can help patients with diabetes lose weight and achieve better glucose control compared to a low-fat diet.
Patients achieved better weight loss and glucose control in a 6-month intervention with a low-carb, high-fat, calorie-restricted diet compared to a high-carb, low-fat diet. This is according to a randomized controlled trial of more than 100 people with type 2 diabetes. The changes were not sustained 3 months after intervention, suggesting that long-term dietary changes are needed to maintain meaningful health benefits. Findings published Internal Medicine Annuals on the 13th of December.
More than 480 million people worldwide are affected by type 2 diabetes. According to the American Diabetes Association, more than 37 million people in the United States alone have diabetes. More than half of people with diabetes also have nonalcoholic fatty liver disease (NAFLD), which can progress to cirrhosis and impair liver function. Previous studies show that losing weight improves both diabetes control and NAFLD, and restricting carbohydrate intake improves control of blood sugar levels.
Scientists from the University of Southern Denmark in Odense, Denmark assigned 165 people with type 2 diabetes to either a low-carb high-fat (LCHF) diet or a high-carb low-fat (HCLF) diet for 6 months. Participants in both groups were asked to consume an amount of calories equal to their energy expenditure. Patients on a low-carb diet were instructed to get no more than 20% of their calories from carbohydrates, but 50-60% of their calories from fat and 20-30% from protein. Participants on a low-fat diet were asked to get about half of their calories from carbohydrates and split the rest equally between fats and proteins.
The authors found that people on a low-carb diet reduced hemoglobin A1c by 0.59 percent more than on a low-fat diet, and also lost 3.8 kg (8.4 pounds) more weight compared to the low-fat group. Low-carb dieters also lost more body fat and reduced their waist circumference. Both groups had higher high-density lipoprotein cholesterol and lower triglycerides at 6 months.
However, changes were not sustained 3 months after intervention, suggesting that dietary changes must be sustained over the long term to maintain effects. The liver was not affected by the high fat intake in the low-carb group: The researchers found no difference in the amount of liver fat or inflammation between the two groups.
Reference: “The Effect of a Calorie-Restricted Low-Carb, High-Fat Diet vs. High-Carb, Low-Fat Diet on Type 2 Diabetes and Non-Alcoholic Fatty Liver Disease: A Randomized Controlled Study”, Camilla Dalby Hansen, MD, Eva-Marie Gram-Kampmann, MD, Johanne Kragh Hansen, MD, Mie Balle Hugger, MD, Bjørn Stæhr Madsen, MD, PhD, Jane Møller Jensen, RD, Sara Olesen, MD, Nikolaj Torp, MD, Ditlev Nytoft Rasmussen, MD, PhD, Maria Kjærgaard, MD, Stine Johansen, MBBS, Katrine Prier Lindvig, MD, Peter Andersen, MSc, Katrine Holtz Thorhauge, MD, Jan Christian Brønd, cand.scient, PhD, Pernille Hermann, MD, PhD, Henning Beck-Nielsen, MD , DMSc, Sönke Detlefsen, MD, PhD, Torben Hansen, MD, PhD, Kurt Højlund, MD, DMSc, Maja Sofie Thiele, MD, PhD, Mads Israelsen, MD, PhD, and Aleksander Krag, MD, PhD, 13 December 2022, Internal Medicine Annuals.