Severe injuries produce profound hypermetabolic stress responses which cause severe loss of lean body mass and muscle wasting, immunologic compromise, slowed wound healing, and related bone loss, all which contribute to increased morbidity, mortality, and prolonged recovery from injury. The results of hypermetabolism persist for weeks to months depending on the severity of the insult. Massive burns can cause severe catabolism and are an excellent model to study the general effects of injury on protein metabolism. Severe burns are characterized by dramatic increases in energy utilization and alterations in the metabolism of carbohydrates, fat, and protein.