Energy Density and Glycemic Load are Associated with Weight Gain during Pregnancy

Excessive weight gain during pregnancy has been suggested as a pathway for the development of obesity in women. Glycemic load (the product of glycemic index and carbohydrate intake) and energy density (calories per gram of food consumed) are dietary factors that are thought to contribute to increased weight gain. We examined the association of glycemic load and energy density, measured by a food frequency questionnaire, with gestational weight gain, expressed as a continuous variable (kgs) and as a ratio of the observed weight gain to the expected using the Institute of Medicine's recommendations. Data are from the Pregnancy, Infection, and Nutrition Study, a longitudinal, prospective pregnancy cohort study (n=1256). Four generalized linear models were made to test the associations. Results showed that energy density is associated with gestational weight gain after controlling for BMI, parity, smoking, SES and physical activity. The glycemic load is also predictive of these outcomes but is highly correlated with total energy intake (r=.91). When glycemic load is adjusted for energy intake, using the residual method, it no longer predicts weight gain and the direction of the association becomes negative. These findings suggest that energy density may influence gestational weight gain and that total energy intake is a stronger predictor of weight gain than glycemic load. (Funding NIDDK# DK061981 )