Maternal nutrient restriction

Abstract

Objective: To determine the effects of maternal nutrient restriction of dams on two different diets on body weight, food intake, feed efficiency, perirenal fat pads, and body fat percentage of offspring. Hypothesis: We hypothesize that maternal nutrient restriction with both standard and high-fat chow adversely affects the genetic programming involved in the regulation of food intake inthe offspring. Design: The first experiment aimed to determine the effects of maternal nutrient restriction with standard chow (11% fat) on appetite regulation of offspring. Pregnant mice were fed standard chow either ad libitum throughout gestation or were restricted by 25% during the last trimester. This process was repeated to obtain third generation progeny. The purpose of the second experiment is to examine potential augmented (compared to experiment 1) alterations in the regulation of appetite in offspring in response to a maternal high-fat diet (45% fat) followed by restriction. The same method was utilized with the following change. Once weaned (at 3 weeks of age), each generation of pups was fed high-fat chow for 8 weeks prior to breeding, when females were divided into two groups. Both were fed a high-fat diet until the last trimester, when one was continued on ad libitum food and the other was restricted by 25%. Subjects: C57BL/6 strain of mice were used. Measurements: Weekly body weights (grams) and daily food intakes (grams) were measured, and food intake converted into kilocalories (kcal) of each respective diet. Feed efficiency was calculated from food intake and body weight measurements. In the high-fat-fed animals, perirenal fat pads were weighed (grams) and used to estimate body composition with a ratio to final body weight. Results: The current study did not reveal any statistically significant negative alterations in appetite and energy regulation of offspring from two maternal treatments or diets. It did, however, reveal that maternal malnutrition, either from undernutrition (a restricted intake) or overnutrition (HF diet) is likely to have adverse effects in the offspring, including higher average body weights and feed efficiencies, as well as larger perirenal fat pads with a corresponding higher body fat percentage.

INDEX WORDS: fetal programming; maternal treatment; maternal diet; offspring regulation