Weight gains and fat accumulation in rats subjected to periods of caloric restriction

¹ Department of Physiology, University of Rochester School of Medicine and Dentistry, Rochester, New York

It was previously observed that weanling rats subjected to several days of caloric intake just sufficient to maintain weight and then fed ad libitum developed enhanced rates of lipid accumulation. Animals so treated gained weight and accumulated fat at a rate greater than did animals fed ad libitum from weaning. The objective of the present study was to determine the conditions of restricted intake that resulted in the greatest stimulation of lipogenesis and to evaluate the effect of an initially elevated rate of fat accumulation on later body composition. Maximal stimulation of lipogenesis was found to follow 6 days of caloric restriction on a diet high in carbohydrate. Differences in body weight and fat content previously observed after 6 days were not maintained. By the 12th day of ad libitum feeding, body weight and fat content of control animals and those with elevated lipogenesis were the same. Animals subjected to periods of caloric restriction alternating with periods of ad libitum intake showed, during unrestricted feeding, rates of weight gain and fat accumulation greater than that of animals fed ad libitum continuously.