Metabolic advantages of higher protein diets and benefits of dairy foods on weight management, glycemic regulation, and bone

Abstract

The Inst. of Medicine and World Health Organization have determined that 0.8 to 0.83 g protein·kg(-1) ·d(-1) is the quantity of protein required to establish nitrogen balance in nearly all healthy individuals. However, consuming higher protein diets may be metabolically advantageous, particularly for overweight and obese adults attempting weight loss, and for physically active individuals such as athletes and military personnel. Studies have demonstrated that higher protein diets may spare lean body mass during weight loss, promote weight management, enhance glycemic regulation, and increase intestinal calcium absorption, which may result in long-term improvements in bone health. The extent to which higher protein diets are beneficial is largely attributed to the digestive and absorptive properties, and also to the essential amino acid (EAA) content of the protein. Proteins that are rapidly digested and absorbed likely contribute to the metabolic advantages conferred by consuming higher protein diets. The EAA profiles, as well as the digestive and absorptive properties of dairy proteins, such as whey protein and casein, are particularly advantageous because they facilitate a rapid, robust, and sustained delivery of EAAs to the periphery. This article reviews the scientific literature assessing metabolic advantages associated with higher protein diets on weight management, glycemic regulation, and bone, with emphasis given to studies evaluating the potential benefits associated with dairy.

Keywords: body weight; bone; branched-chain amino acids; casein; muscle; whey.