Low Carbohydrate and Low Fat Diets with Equal Protein Content Lead to Similar Improvements in Body Composition and Glucose Tolerance in Obese Mice subjected to Caloric Restriction

Abstract

BackgroundReported differences in effects of low and high carbohydrate diets on weight control and metabolic health are controversial. We aimed to examine if such diets induce different improvements in body composition and glucose tolerance under conditions of caloric restriction (CR) in obese mice. MethodsMale C57BL/6J mice (n = 20) were fed obesogenic diet (45 and 17.5% kcal from fat and sugar) ad libitum for 18 weeks and then subjected to 6-week CR which progressively increased up to 40% using either Low Fat diet (20, 60, 20% kcal from fat, carbohydrate, protein, n = 10) or Low Carb diet (20, 60, 20% kcal from carbohydrate, fat, protein, n = 10). Mice fed regular chow diet ad libitum served as controls (n = 10). Body mass, hind limb muscle mass, fat mass, energy expenditure and glucose tolerance were compared between the groups. ResultsLow Fat and Low Carb groups had similar body mass (p > 0.05) prior to CR which was 30% greater compared to control group (p 0.05). Weight loss was mainly due to fat loss in both groups. Energy expenditure of freely moving mice did not differ between the groups (p > 0.05). Intraperitoneal glucose tolerance test improved compared to control group (p 0.05). ConclusionsDietary carbohydrate or fat content when protein is equated does not play a significant role for body composition and metabolic health benefits of caloric restriction in obese mice.