HealthDay News — Breastfeeding is inversely associated with body mass index z scores (BMIzs) measured at 12 months, and the association is attenuated with formula supplementation by 6 months, according to a study published online Sept. 24 in Pediatrics.
Meghan B. Azad, PhD, from the University of Manitoba in Winnipeg, Canada, and colleagues examined breast milk feeding, type of supplementation, and feeding in hospital in 2553 mother-infant dyads.
The researchers found that 97% of the mothers initiated breastfeeding, with a median breastfeeding duration of 11 months. Seventy-four percent of the infants received solids before 6 months. Overall, 55% and 27% of “exclusively breastfed” infants received some expressed breast milk and briefly received formula in hospital, respectively. Higher BMIzs were seen in association with all feeding styles compared with exclusive direct breastfeeding at three months (adjusted β, +0.12 for some expressed milk, +0.28 for partial breastfeeding, and +0.45 for exclusive formula feeding). These associations were not altered by brief formula supplementation in hospital, as long as exclusive breastfeeding was established and sustained for at least 3 months. Formula supplementation by 6 months, but not solid food supplementation, was associated with higher BMIzs (adjusted β, +0.25). Similar results were seen for weight gain velocity.
“This study provides new evidence to inform feeding recommendations and guide further research about infant feeding practices and how they influence the development and prevention of childhood obesity,” the authors write.
One author disclosed ties to the infant nutrition industry.