Food intake and weight of lactating rats maintained on different protein-calorie diets, and pup growth

RESUMO

Studies on rats maintained on low-protein-calorie diets during the lactation period show that food intake decreases. This process results in weight loss and a delay in litter development. The purpose of the present study was to determine the alterations in food intake, maternal weight and litter growth during lactation when dams were exposed to diets with different levels os protein and carbohydrate. Female Wistar rats receiving one of 4 different diets, A (N = 14), B (N = 14), C (N = 9) and D (N = 9), were used. Diet A contained 16 per cent protein and 66 per cent carboydrate; diet B, 6 per cent protein and 77 per cent carboydrate; diet C, 6 per cent protein and 66 per cent carboydrate; diet D, 16 per cent protein and 56 per cent carboydrate. Thus, C and D diets were hypocaloric, while A and B were isocaloric. The intake of a low-protein diet in group B and C affected the weight of dams and litters during the last two weeks of lactation, while the low-calorie diets limited the growth of D litters at 21 days compared with A litters, but had no effect on the weight of D dams. Group B showed an increase in intake during the first five days of lactation, resulting in a behavioral calorie compensation due to the increase in carboydrate content, but the intake decreased during the last part of lactation. Food intake regulation predominantly involves the recruitment of a variety of peripheral satiety systems that attempt to decrease the central feeding command system.