The influence of (-0-Hydroxycitrate(HCA), shown to be a competitive inhibitor of adenosine 5-triphosphate(ATP) citrate lyase, on food intake and body weight, serum triglyceride and cholosterol level, in vivo rates of fatty acid and cholesterol synthesis, and fat cell number and size was investigated. 3 groups of female, 5 weeks old Sprague Dawley rats, 8 animals each, were ad libitum meal-fed or pair-fed(3 hours from 10 : 00 to 13 : 00) AIN based high glucose diet for a total period of 8 weeks. Providing normolipidemic rats orally with 400mg of HCA formula containing approximately 20mg of HCA 1 hour prior to daily feeding schedule significantly depressed in vivo hepatic rates of fatty acid and cholesterol synthesis in the liver and adipose tissue. Serum triglyceride and cholesterol levels were significantly reduced by HCA. At the end of treatment period, the rats administered with HCA resulted in a significantly reduction in body weight gain. The reduction in weights was attributable to a significant decrease in fat cell size with a smaller extent, but not significant, reduction in fat cell number. Rats receiving HCA demonstrated less food intake than the controls ; however, this decreased caloric intake was not fully responsible for the HCA induced depression of hepatic and adipocytic lipogenesis, since experiment using pair-fed cojntrol rats showed, less magnitude but similar results. Both a anorectic and an antilipogenic properties of HCA seem to be responsible for this weight reduction activity of HCA. The outcome of this study suggest that metabolic regulation may be a feasible approach to the control of obesity and hyperlipidemia.