The objective of this project is to evaluate the contribution of learned food aversions to the appetite and weight loss induced by tumors and anti-tumor therapy. The proposed studies are based on our recent demonstrations (a) that learned aversions to specific foods can occur in cancer patients receiving GI toxic chemotherapy; and (b) that in animals, tumor growth alone, in the absence of any aversive therapy, can produce aversions to the available diet. Using an experimental animal model we intend to (a) define the conditions under which aversions to foods are acquired as a consequence of tumor growth and/or chemotherapy; (b) evaluate whether learned food aversions contribute to anorexia; and (c) evaluate intervention approaches for minimizing or eliminating these learned food aversions. In the clinic we intend (a) to continue to define the conditions under which learned food aversions are acquired as a consequence of GI toxic chemotherapy as well as to evaluate their impact on the nutritional status of cancer patients; and (b) to evaluate the effectiveness of selected intervention methods in preventing learned food aversions in cancer patients receiving GI toxic chemotherapy.