Soy protein-based compared with casein-based diets fed during pregnancy and lactation increase food intake and characteristics of metabolic syndrome less in female than male rat offspring

We hypothesized that soy protein (S)-based diets fed during pregnancy and lactation increase food intake and the presence of characteristics of the metabolic syndrome to a lesser extent in female than in male rats. Soy protein- and casein (C)-based American Institute of Nutrition-93G diets were fed to 2 groups (n = 12 per group) of pregnant Wistar rats from day 3 of gestation and throughout lactation. Their effects on characteristics of metabolic syndrome and food intake regulation in female pups maintained for 15 weeks on the C diet were compared. Body weight (BW) and food intake (FI) were measured weekly. Fat pad mass was measured at birth, at weaning, and at week 15. Glucose and insulin tolerance tests were conducted at weeks 8 and 12; and systolic and diastolic blood pressures were measured at weeks 4, 8, and 12. Plasma was collected at weaning and at the end of the studies for glucose, insulin, glucagon-like peptide 1, peptide YY, and ghrelin. Food intake in response to protein preloads was measured at week 7. Feeding the S diet throughout gestation and lactation resulted in higher systolic blood pressure (P < .005), FI (P < .05), and glucagon-like peptide 1 and lower peptide YY at weaning and higher BW during weeks 11 to 15 and fat pad mass at week 15 (all Ps < .05). However, no sign of insulin resistance was found; nor was short-term FI in response to protein preloads affected. In conclusion, S- compared with C-based American Institute of Nutrition-93 G diets consumed throughout gestation and lactation increased BW and FI later and resulted in fewer characteristics of metabolic syndrome in female than in male offspring.