A succinct review of hundreds of studies on the regulation of protein mass and protein turnover in the human body. The book summarizes the biochemistry of protein synthesis and breakdown, and explains the methods that are used to examine protein metabolism in humans, together with their limitations. Chapters review the effects of nutrition, hormones, metabolic substrates, and physical activity, while various topics of clinical interest include cancer, diabetes, tissue injury, pregnancy, renal disease, muscular dystrophies, and other conditions. Normal values are presented for turnover of proteins in the whole body and individual organs, and for turnover of many individual proteins. This is thus a valuable resource for physiologists, nutritionists, and clinicians interested in the regulation of body protein stores in health and disease. For scientists primarily interested in the basic aspects of protein metabolism, it shows how the basic knowledge is being applied to the study of humans.