This volume provides a comprehensive and objective survey of the physiology and nutritional biochemistry of dietary proteins, peptides and amino acids. Special attention is paid to their contributions to enteral nutrition and, particularly, to the part that these nutrients and substrates play in the nutritional support in various clinical settings. Having examined the new, exciting information about the role of the intestine in the utilization of proteins and their products of digestion, the focus turns to the consequences that catabolic stress and immunologic stimulation have on the qualitative and quantitative aspects of the protein/amino acid metabolism. These aspects are considered with relation to the support of body protein and amino acid homeostasis and requirements in patients with injury, severe infection, gastrointestinal malfunction, cancers and renal disease. Finally, as there is clearly a knowledge gap in this area of clinical/enteral nutrition, the opportunities for future research are highlighted. Written by leading nutritional scientists and clinical investigators, this publication will help practitioners as well as clinical and basic scientists to understand the opportunities enteral nutrition offers in the clinical management of patients.