Animals and humans with tumors may display profound cachexia during the course of illness. In some instances, weight loss may be an initial manifestation of cancer, occurring before the neoplasm is widespread. Anorexia, nausea, vomiting, and diminished food intake may be important factors in contributing to the development of cachexia in far advanced cancer. In addition, inanition may arise from diminished intestinal absorption, blood loss, tissue ulceration and necrosis, or infection and other factors.(70) Disturbances in the metabolism of lipids, amino acids, carbohydrates, and electrolytes have all been described in patients with cancer, but the precise mechanisms underlying weight loss and malnutrition remain uncertain.(11,13) Tumors have been referred to as “nitrogen traps” that derive their amino acid supplies at the expense of the animal or human host.(23,44) It appears that, when the supplies of dietary nitrogen are limited, tumor competes for them more successfully than normal host tissues.