Bioactive peptides are used to enhance the body's antioxidant status, antisepsis capacity, immune function, anti-inflammatory capacity, mineral absorption, and appetite. They can also mitigate major metabolic derangements arising from chronic illnesses which result in unwanted weight loss. Presenting data from human studies, clinical trials, and recent research findings, this work summarizes the applications and benefits of this therapy. The book covers host response, quality factors, protein economics, and muscle loss. It includes case studies on aging, AIDS, COPD, diabetes, inflammatory bowel disease, kidney failure, and tuberculosis.