An overview of the metabolic response to acute traumatic brain injury is presented. The consequences of hypermetabolism, hypercatabolism, and an altered immune function are discussed. Once a person with acute traumatic brain injury develops this hyperdynamic state, the resultant excessive protein breakdown ensues. This can lead to malnutrition. The feeding methods used to prevent malnutrition are discussed, along with the proper alimentation to provide to diminish the hyperdynamic state and improve immune function.