Early infant growth trajectories have been linked to obesity risk. The aim of this study was to examine early infant feeding practices in association with anthropometric measures and risk of overweight/obesity in childhood. A total of 2492 children from Upstate KIDS, a population-based longitudinal cohort, were included for the analysis. Parents reported breastfeeding and complementary food introduction from 4 to 12 months on questionnaires. Weight and height were reported at 2-3 years of age and during later follow-up at 7-9 years of age. Age and sex z-scores were calculated. Linear mixed models were conducted, adjusting for maternal and child sociodemographic factors. Approximately 54% of infants were formula-fed at <5 months of age. Compared to those formula-fed, BMI- (adjusted B, -0.23; 95% CI: -0.42, -0.05) and weight-for-age z-scores (adjusted B, -0.16; -0.28, -0.03) were lower for those exclusively breastfed. Infants breastfed for ≥12 months had a lower risk of being overweight (aRR, 0.33; 0.18, 0.59) at 2-3 years, relative to formula-fed infants. Compared to introduction at <5 months, the introduction of fruits and vegetables between 5 and 8 months was associated with lower risk of obesity at 7-9 years (aRR, 0.45; 0.22, 0.93). The type and duration of breastfeeding and delayed introduction of certain complementary foods was associated with lower childhood BMI.
Keywords: breastfeeding; child development; childhood obesity; complementary feeding; early infant feeding practices; nutrition; overweight.