Effects of dietary protein on glucose homeostasis

Purpose of review Despite the proven efficacy of the established high-carbohydrate diets for treatment and prevention of obesity and type 2 diabetes, alternative diets including high-protein, high-fat, low-carbohydrate diets have become increasingly popular. The purpose of this review is to discuss potential effects of increased protein intake on glucose metabolism and body weight. Recent findings Recent intervention trials revealed that, in the short-term, the intake of proteins at the expense of carbohydrates increases satiety and thereby lowers intake of calories. High protein intake augments prandial insulin secretion and might thereby improve glycaemic control in type 2 diabetic patients. On the other hand, epidemiological studies suggest that chronic high dietary protein intake is associated with increased incidence of type 2 diabetes. Furthermore, a short-term increase in plasma amino acid concentrations has been shown to directly induce insulin resistance in skeletal muscle and stimulate endogenous glucose production. Summary Dietary proteins and amino acids are potent modulators of glucose metabolism and might also affect satiety and energy intake. However, due to the lack of well-controlled long-term studies the optimal macronutrient composition for treatment and prevention of obesity and type 2 diabetes is not known.