The relationship between dietary intake and body composition changes over the course of pregnancy

The purpose of this study was to assess body composition and dietary intake changes during pregnancy and to examine the relationship between dietary intake and body composition during pregnancy. Twelve pregnant women (30.0 ± 6.5 years) participated in the observational, prospective study. Dietary intake was assessed by a semi-quantitative food frequency questionnaire, using two retention intervals: dietary intake during the year prior to pregnancy and dietary intake during the previous month. Height, weight, and bioelectrical impedance analysis were obtained using standard procedures and were utilized to establish body fat. Dietary intake and body composition measurements were taken once during each trimester (measurement one mean gestational age: 9.6 ± 3.3 weeks; measurement two mean gestational age: 20.3 ± 1.3 weeks; and measurement three mean gestational age: 31.8 ± 1.4 weeks), with 100% of the subjects completing the first two measurements and 58% of the subjects completing all three measurements. Results of the food frequencies indicated that while energy and macronutrient intakes increased over pregnancy, no statistically significant changes were found. Anthropometric measurements revealed that mean weight gain was 7.5 ± 5.4 kilograms and mean gain in body fat was 4.7 ± 3.3 kilograms. Changes in weight and body fat were statistically significant (p ≤ 0.05) for each measurement, indicating an overall increase in weight and body fat during pregnancy. Correlation coefficients indicated there was a statistically significant association (p ≤ 0.05) between changes in Food Quotient (a measurement of macronutrient composition of the diet) and changes in weight, body fat, and body fat percent for the period between the first and second measurement. A statistically significant association (p ≤ 0.05) was also found between changes in Food Quotient and changes in body fat percent between the second and third measurements. Multiple stepwise regression analysis found that the most consistent dietary variable that partially accounted for a significant amount of change in body fat over the course of pregnancy was change in Food Quotient. These results indicate that body fat deposition and weight gain over the couse of pregnancy may be influenced by dietary fat and carbohydrate intake, with a high-fat, low-carbohydrate diet associated with greater weight gain and fat deposition during pregnancy.