Effect of caloric restriction during pregnancy on maternal and fetal body composition in the obese Sprague-Dawley rat.

The effects of 15, 30 or 50% caloric restriction during pregnancy on maternal and fetal compartments was determined in obese Sprague-Dawley rats. Pregnant and nonpregnant animals were assigned on a weight basis to one of the dietary treatments. All nutrients, except calories, were fed at levels to meet dietary requirements. Animals were killed on day 20 of treatment and fetuses were taken by Caesarian section. Pregnant animals achieved positive weight gain during 20 days of gestation at all levels of caloric restriction. Nonpregnant animals lost body weight when calories were restricted by 30 and 50%. Number of fetuses, fetal body nitrogen, and pup weight were not statistically different (P less than 0.05) among groups. Animals fed the 30 and 50% calorie-restricted diets showed a significant (P less than 0.05) decrease in total-body fat. Percent carcass protein tended to increase as dietary caloric restriction increased. The fetal compartment was apparently not affected by maternal caloric restriction up to 50% during pregnancy provided that all other nutrients were supplied in adequate amounts. Maternal stores were adversely affected at levels of 30 and 50% caloric restriction.