The effect of dietary caloric restriction during pregnancy on maternal and fetal body composition in the obese Sprague Dawley rat

Abstract

Obese, female Spraque-Dawley rats were assigned, on a weight basis, to one of three dietary treatments: ad lib, 15% caloric restriction, and 30% caloric restriction. All other nutrients were fed at levels to meet dietary requirements. Each treatment groups was further sub-divided into pregnant and non-pregnant animals. Rats were sacrificed on Day 20 of gestation and fetuses were taken by Caesearean section. Maternal and fetal body composition, maternal serum protein concentrations were examined. Weight change for pregnant rats was +85 gms in the ad lib-fed group, +82 gms in the 15% calorie restricted group, and +56 gms in the 30% calorie restricted group. Weight changes for the non-pregnant rats for 20 days of dietary treatment were +53 gms, +18 gms, and -7 gms respectively. Fetal body nitrogen and average pup weight did not differ between treatment groups. Total maternal body nitrogen was not decreased during pregnancy in ad lib-fed and 15% calorically restricted animals. It did decrease in 30% calorically restricted animals. Ad lib-fed animals showed no changes in total body fat. Animals on the 15% calorie restriction diet showed no change in total body fat percentages. Animals on the 30% calorie restriction showed a 10% decrease in total body fat content as compared to the ad lib and 15% restricted pregnant group. Serum protein levels decreased in pregnant animals as caloric restriction increased. Serum protein levels in nonpregnant animals increased as dietary restriction increased. The fetal compartment was not affected by maternal caloric restriction up to 30% provided that all other nutrients were adequate. Maternal stores were affected at a level of 30% caloric restriction.