Health issues of whey proteins: 1. Protection of lean body mass

Loss of muscle mass as a consequence of changes in protein metabolism during periods of catabolic stress is a serious complication in a variety of conditions. These conditions are weight loss programs, sarcopenia in the elderly and several clinical states. It appears from many studies that improved protein nutrition by ingestion of high-quality proteins can help to decrease loss of lean body mass. Essential amino acids, especially branched-chain amino acids (BCAA) and cysteine are implicated as key factors in this regard. Since whey protein is one of the best naturally occurring proteins in terms of digestibility and concentration of BCAA and cysteine, this paper reviews the significance of whey protein for protection of lean body mass. It is concluded that whey proteins will he, to reduce unwanted loss of muscle mass during weight loss regimens. Ingestion of whey will contribute to an increase of muscle mass during exercise programs, designed to prevent or reduce sarcopenia in the very old. Moreover, ingestion of whey protein is useful in the prevention of muscle mass loss in (clinical) catabolic conditions. The extent to which whey protein offers a specific nutritional advantage in humans over other high-quality proteins needs to be assessed.