A new study of 2553 mother-baby pairs in Canada looked at body mass index of infants at 12 months and how they were fed. The study will be published in the American Academy of Pediatrics’ journal “Pediatrics.”
What they found is that babies who were exclusively fed breast milk for at least three months had a lower BMI than babies who were given mainly formula. The introduction of solid food before six months didn’t seem to matter, and if a mother supplemented a little bit with formula while in the hospital, that didn’t matter as long as she established exclusive breastfeeding afterwards.
What did matter, interestingly, is how the breast milk was delivered to the baby. Mothers who exclusively fed at the breast had babies with lower BMIs than baby’s who received expressed breast milk in a bottle. Regardless of how they got the breast milk, breastfed babies had lower BMI than formula-fed babies.