The overall purpose of the study is to evaluate the effect of depleting proline supply in the nutritional support regimen on proline metabolism in the burn patients, this includes the rate of proline oxidation after burn injury, the rate of proline de novo synthesis from its immediate precursors glutamate and ornithine. The specific aims of the proposed study are: 1) to determine the kinetic status of proline metabolism and whole body proline balance under the following nutritional states: (a) "fasting; (b) regular total parenteral nutrition (TPN); (c)TPN with isonitrogenous depletion of proline, glutamate and ornithine metabolism under nutritional conditions studied in specific aim 1) above.