Prenatal and early postnatal nutritional environments are critical windows for disease development in later life. The aim of this study was to explore the association between maternal dietary intake and neonatal body composition.
Secondary analysis of women enrolled in a randomized controlled trial comparing the effect of a low glycaemic index diet vs a healthy diet in pregnancy at risk of gestational diabetes (n=139). Maternal dietary data was collected using 3-day food records in the second and third trimesters. Neonatal body composition was assessed by air-displacement plethysmography. Infant body composition was expressed as fat mass index [FM (kg)/length (m)2] and fat-free mass index [FFM (kg)/length (m)2].
Using linear regression, adjusted for confounders, second trimester maternal dietary carbohydrate (%E) was inversely related to offspring FFM index (β = -0.196, P = 0.050, n=96), while total fat and saturated fat were positively associated (%total fat, β = 0.241, P = 0.016; %saturated fat, β = 0.250, P = 0.012, n=96). In the third trimester, intake of total fat and saturated fat was positively associated with FM index (%total fat, β = 0.224, P = 0.037; %saturated fat, β = 0.216, P = 0.036, n=88), while the quantity and quality of carbohydrate was inversely associated with both FM index (%carbohydrate, β = 0.243, P = 0.037) and FFM index (GI, β = -0.267, P = 0.013).
Fetal body composition may be influenced by maternal diet, particularly the quantity and quality of fat and carbohydrate. Both FFM and FM index appear to be increased by higher fat intake (including saturated fat), but reduced by higher intakes of carbohydrate, particularly from high GI sources. Whether these associations are causal requires further study.