The primary objective of the proposed research is to gather basic information on the mechanisms by which alterations in lipid metabolism may influence the feeding behavior of normal and insulin-deficient diabetic rats. The research plan is to: 1) characterize the metabolic changes in two situations in which lipid metabolism appears most likely to affect food intake, and 2) alter lipid metabolism in these situations with drugs and measure resulting changes in food intake. The metabolic measures include blood concentrations of free fatty acids, triglycerides, and ketones as well as adipose tissue lipoprotein lipase activity. A few indices of carbohydrate metabolism will be included in order to extend the metabolic profiles. The two situations to be studied are recovery from insulin-induced overeating and suppression of food intake following ingestion of fat.