Effects of a low-glycaemic index diet during pregnancy on offspring body composition: a pilot study (#206)
High maternal blood glucose levels during pregnancy contribute to adverse pregnancy outcomes, including fetal overgrowth and offspring obesity. Some studies suggest that a low glycaemic index (low-GI) diet in pregnancy may have beneficial effects on fetal growth but the effects on body composition of offspring are unknown. The aim of this study was to explore the effects of low-GI and conventional high-fibre (HF) diets on offspring body composition at birth and at 3 months of age.
This study is a pilot follow-up study of offspring of mothers with one or more risk factors for GDM, who participated in a larger randomized controlled trial (n=139) comparing two diets during pregnancy. Offspring body composition was assessed at birth and at 3 months of age by air-displacement plethysmography.
A total of 59 women (mean ± SD pre-pregnancy BMI 26 ± 5kg/m2) and their offspring joined the study (42% of the original cohort). Of these, 17 women (29%) developed GDM. There was a significant difference in dietary GI between groups (low-GI 51 ± 1 vs HF 57 ± 1, p < 0.001). Birth weight (kg) was lower in the low-GI group (3.37 ± 0.79) compared to the HF group (3.61 ± 0.85, p = 0.038), as was birth weight z-score (low-GI 0.13 ± 0.17 vs HF 0.65 ± 0.16, p=0.034). However, there was no significant difference in fat mass or fat-free mass. At 3 months of age, there were no significant differences between diet groups in growth parameters or body composition.
Birth weight and birth weight z-score were within normal bounds, but lower in offspring of women who were randomized to a low GI diet vs conventional high fibre diet during pregnancy and agreed to follow up. Both fat mass and fat-free mass are reduced proportionately.