FOOD-INTAKE AND WEIGHT OF LACTATING RATS MAINTAINED ON DIFFERENT PROTEIN-CALORIE DIETS, AND PUP GROWTH

Studies on rats maintained on low-protein-calorie diets during the lac tation period show that food intake decreases. This process results in weight loss and a delay in litter development. The purpose of the pre sent study was to determine the alterations in food intake, maternal w eight and litter growth during lactation when dams were exposed to die ts with different levels of protein and carbohydrate. Female Wistar ra ts 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% protein and 66% carb ohydrate; diet B, 6% protein and 77% carbohydrate; diet C, 6% protein and 66% carbohydrate; diet D, 16% protein and 56% carbohydrate. Thus, C and D diets were hypocaloric, while A and B were isocaloric. The int ake of a low-protein diet in groups B and C affected the weight of dam s and litters during the last two weeks of lactation, while the low-ca lorie 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 carbohydr ate content, but the intake decreased during the last part of lactatio n. Food intake regulation predominantly involves the recruitment of a variety of peripheral satiety systems that attempt to decrease the cen tral feeding command system.