Role of nutrients in the regulation of in vivo protein metabolism in humans

Nutrients regulate protein metabolism both in an acute fashion and on a lon g-term basis. The ingestion of meals is associated with a dramatic switch f rom an overall catabolic state to a state of net protein anabolism. The acu te response of protein metabolism to meal ingestion is mediated, in part, b y an increase in insulin secretion, itself a consequence of glucose absorpt ion. Whereas insulin may primarily suppress rates of proteolysis, amino aci ds are responsible for the stimulation of protein synthesis that follows fo od intake. III the longs run, the effects of nutrition on protein metabolis m depend on the energy supply, the sourer of the energy (carbohydrate versu s fat) and dietary protein intake. Finally, specific amino acids, such as g lutamine, may play an additional role as protein anabolic agents.