[Association of dietary energy intake and energy density with gestational weight gain in Chengdu City]

Objective: To determine the association of dietary energy intake and energy density( ED) with gestational weight gain among pregnant women in Chengdu.

Methods: A total of 503 pregnant women who took the prenatal examination in West China Second University Hospital were selected in the prospective study in 2015. ED, computed as the ratio of energy intake( kcal) per weight( g) of foods( kcal/g), was calculated using three methods as follows:( 1) ED1 included foods only, excluding all beverages;( 2) ED2 included foods and milk;( 3) ED3 included foods and beverages. Energy intake were calculated using dietary data respectively collected in the first, second and third trimester of pregnancy by validated 24-hour recalls, in which ED was calculated based on three calculation method. Data on gestational weight gain was calculated by using pre-pregnancy weight and prenatal weight. Excessive gestational weight gain was determined by the 2009 Institute of Medicine( IOM) recommendations for gestational weight gain. Logistic regression analyses were performed to explore the association of energy intake and ED with excessive gestational weight gain.

Results: The risk of excessive gestational weight gain was higher among pregnant women whose dietary energy intake during the third trimester of pregnancy was higher( OR = 1. 94, 95% CI 1. 18-3. 23). After adjusting for covariates, ED based on foods and milk during the third trimester of pregnancy was identified as a protect factor of excessive gestational weight gain( OR = 0. 56, 95% CI 0. 34-0. 93). Dietary energy intake and ED in the first and second trimester of pregnancy were not associated with excessive gestational weight gain after adjustment of all covariates.

Conclusion: Dietary energy intake in the third trimester of pregnancy might be the risk factor of excessive gestational weight gain, while moderate ED may be the protect factor.