Although weight loss has an adverse impact on cancer patient survival, the ability of caloric provision via total parenteral nutrition (TPN) to favorably influence outcome in chemotherapy-treated populations is not established. In randomized trials, no significant improvement in either response or survival was associated with TPN addition to chemotherapeutic treatment of adult patients with lymphoma, sarcoma, colon cancer, adenocarcinoma and small cell carcinoma of the lung, or testicular carcinoma. In two instances, TPN addition was associated with decreased survival, again raising the concern that caloric support in the absence of effective antitumor therapy might stimulate cancer growth. In any event, the hypothesis that nutritional repletion of a malnourished cancer patient receiving chemotherapy will improve clinical outcome remains to be critically tested, as studies demonstrating sequential improvement in lean body mass have not been reported. Most recently, consideration of potential mechanisms underlying the development of cancer cachexia has led to new strategies for nutritional intervention. For example, hypogonadism or low testosterone levels have been described in male patient populations with advanced cancer and correlated with weight loss and adverse outcome, leading to trial of replacement therapy with nandrolone decanoate. Similarly, the frequent identification of abnormal glucose metabolism in the patients with cancer cachexia has stimulated clinical trials with agents such as hydrazine sulfate and insulin designed to reverse the metabolic abnormality. Whether such efforts designed to alter metabolic abnormalities associated with cancer cachexia will improve clinical outcome will be determined in ongoing clinical trials.