Maternal diet in pregnancy is associated with differences in child body mass index trajectories from birth to adolescence.

backgroundNutrition in pregnancy and accelerated childhood growth are important predictors of obesity risk. Yet, it is unknown which dietary patterns in pregnancy are associated with accelerated growth and whether there are specific periods from birth to adolescence that are most sensitive to these associations.

objectivesTo examine the extent to which 3 dietary indices in pregnancy [Dietary Inflammatory Index (DII), Alternate Healthy Eating Index for Pregnancy (AHEI-P), and Mediterranean Diet Score (MDS)] are associated with child BMI z-score (BMI-z) trajectories from birth to adolescence.

methodsWe examined 1459 mother-child dyads from Project Viva that had FFQ data in pregnancy and ≥3 child BMI-z measurements between birth and adolescence. We used linear spline mixed-effects models to examine whether BMI-z growth rates and BMI z-scores differed by quartile of each dietary index from birth to 1 mo, 1-6 mo, 6 mo to 3 y, 3-10 y, and >10 y.

resultsThe means ± SDs for DII (range, -9 to +8 units), AHEI-P (range, 0-90 points), and MDS (range, 0-9 points) were -2.6 ± 1.4 units, 61 ± 10 points, and 4.6 ± 2.0 points, respectively. In adjusted models, children of women in the highest (vs. lowest) DII quartile had higher BMI-z growth rates between 3-10 y (β, 0.03 SD units/y; 95% CI: 0.00-0.06) and higher BMI z-scores from 7 y through 10 y. Children of women with low adherence to a Mediterranean diet had higher BMI z-scores from 3 y through 15 y. Associations of AHEI-P with growth rates and BMI z-scores from birth through adolescence were null.

conclusionsA higher DII and a lower MDS in pregnancy, but not AHEI-P results, are associated with higher BMI-z trajectories during distinct growth periods from birth through adolescence. Identifying the specific dietary patterns in pregnancy associated with rapid weight gain in children could inform strategies to reduce child obesity.