The benefits of breastfeeding are well documented, but researchers have found a more specific advantage: Nursing directly from the breast is linked to a lower risk of obesity in babies than being bottle fed — even if it’s with pumped breast milk.
While overall, giving babies breastmilk via any method — breastfeeding, pumping, supplementing with formula if needed — is best, children who nursed from the breast had lower body mass indexes at three months old, and researchers believe that it may also decrease their risk of becoming overweight or obese later in life.
The study, published in the American Academy of Pediatrics’ journal Pediatrics, looked at data from 2,553 infant and mother duos who fed using a variety of methods. Some exclusively breastfed, while others nursed for three months before switching to formula, and others bottle-fed, among other combinations.
Babies who breastfed for less than six months gained weight faster, had a higher BMI at 12 months and had a three times greater risk of being overweight compared to those who were solely breastfed.
While the researchers noted these benefits of breastfeeding over bottle feeding, they are not sure why there is a difference.
“Moms who pump go through a lot of effort to do that, and I wouldn’t want them to get the impression that it’s not worth it. But it does raise the question of, if pumped milk is not the same or not as good, why is that? And what should we be doing to support moms better around breastfeeding if that’s what they want to do?” study author Meghan Azad, research scientist at the Children’s Hospital Research Institute of Manitoba, told CNN.
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One researcher, who did not work on the study, speculated to CNN that bottle-fed milk may take on different properties when frozen and then thawed, which could contribute to higher weight gain, or perhaps nursing from the breast helps with portion control.
The study authors also found that babies who started getting formula supplementation at six months had higher BMIs than those who continued to breastfeed while beginning to eat solid food, which is in line with doctors’ recommendations.
The researchers, who are Canadian, said that these results are concerning considering the lack of a standardized paid leave in the United States.
“Many moms, they have to go back to work after a few weeks, so if they want to continue providing breast milk, they have to do it by pumping,” Azad said.
But, she emphasized, overall, fed is best.
“Any amount is better than none,” Azad said. “The more you can do, the better. Every feed counts.”