The branched-chain amino acids are unique in chemical structure, metabolism, and that they are essential in the diet of both humans and monogastric food animals. Whether you are a health professional looking to increase your Knowledge of amino acid nutrition on disease, health, and aging, or an agriculture scientists looking to broaden your knowledge of factors influencing amino acid requirements, this text is a must. This book represents three diverse sections encompassing eleven chapters in total. Section one, being the largest, consist of six chapters addressing the role of branched-chain amino acids in domestic animal and human health. Endocrine and antioxidant systems affected by branched-chain amino acid status are presented, as well as biochemical and molecular mechanisms behind their responses. Moreover, the pros and cons of branched-chain amino acid therapy and balance in sports nutrition, catabolic injury recovery, disease, and successful aging are presented. The second and third sections of this text are similarly unique, in that they contain five chapters addressing diet needs, digestion, intestinal metabolism, absorption, and subsequent whole-body metabolism at the biochemical and molecular level. Further, two different meta-analyses have been composed using independent branched-chain amino acid data for assessment of food animal needs, in addition to providing insights for controlling metabolic homeostasis via diet formulation. Lastly, and specific for food animal production, the most limiting branched-chain amino acids in swine and poultry diets (e.g., valine and isoleucine) are poised to gain popularity and further price competitiveness in their crystalline L-amino acid forms, and thus, have tremendous environmental implications in terms of planetary nitrogen and water cycling.