Breastfeeding helps prevent obesity

Science You Can Use: Study says the act of breastfeeding, not the milk, is what protects against obesity.

By Tanya Lieberman, IBCLC | Posted on May 19, 2012 | No Comments |

When it comes to obesity and breastfeeding, here’s what we know: Not breastfeeding increases the risk of childhood obesity (a 32% excess risk, according to the Surgeon General).
And here’s what we don’t know: Why and how? Is it something in the milk? Is it something about the feeding method? Is it something in formula?
A new study, which confirms prior research, investigated the relationship between obesity risk and breastfeeding, bottle-feeding, and what goes in the bottles, and concludes that feeding method plays a key role in the amount of weight babies gain and their future risk of childhood obesity.
This longitudinal CDC study followed nearly 2,000 babies from birth to one year, gathering at least three weight measurements. Babies were categorized into one of six feeding method categories. Here’s what the study found:

Compared with strictly breast-fed infants, babies who exclusively bottle-fed gained 71 or 89 g more per month when fed either nonhuman milk only (P < .001) or expressed human milk only (P < .02), respectively. But, “they gained only 37 g more per month when fed both expressed human milk and nonhuman milk (P = .08).”
The researchers also determined that babies who breast-fed and drank expressed human milk from bottles gained weight in a similar manner to infants who exclusively breast-fed, whereas infants who both breast-fed and drank from bottles of nonhuman milk gained 45 g more per month (P < .001), suggesting that “supplementing breastfeeding with expressed breastmilk would be preferable to supplementing breastfeeding with nonhuman milk.”

Why would it be that the effect of breastfeeding would be different when feeding pumped milk? The authors suggest: “In contrast to infants fed at the breast who may need to actively suckle, formula-fed infants are more likely to be passive in the feeding process, and caregivers’ control might undermine infants’ capability for self-regulation to balance energy intake against internal cues of hunger and satiety.” This is consistent with earlier preliminary research suggesting that found that breastfed children could more easily determine when they were full.
In other words, when parents are in control of feeding, we tend to push babies to eat past the point of fullness. You could call this the “just finish it!” instinct.
(And I wonder – with no evidence but my own pumping experience and that of moms I’ve worked with - if this urge might be particularly strong for mothers who have done the dreary work of pumping and don’t want to see a single drop go to waste.)
The take home message: It’s not just about the milk. The act of feeding itself may play an important role in establishing a healthy weight and healthy self-regulation of food intake.
What to do if you’re a bottle-feeding mom? If you want to practice bottle-feeding which supports healthy weight and feeding behavior, please check out our post, “How to Bottlefeed as You’d Breastfeed.”
Did you bottle and breastfeed? Ever find yourself resisting the urge to make your baby finish a bottle? If you breastfed, do you think your baby could recognize when he/she was full?