The Wet Nurse Angele Feeding Julie Manet

Bad Assumptions About Feeding Infants and Obesity Risk

Will the perfect approach to feeding infants cut their risk of obesity? Perhaps. But if someone tells you they know that perfect approach, be careful. Evidence for such suppositions doesn’t yet exist.

Infant-Led Weaning?

One supposition has long been that Baby-Led Introduction to Solids (BLISS) would lead to a longer duration of breastfeeding and a lower risk of obesity. Plenty of observational studies suggested that this might be true. Let the baby lead the way. It all seems very plausible.

Except it’s not true.

Researchers from New Zealand conducted a randomized clinical trial. Mothers were randomized to a control group or a BLISS intervention. In the control group, mothers received standard prenatal care. In the intervention group, they received more lactation support to extend breastfeeding and delay introducing solid foods.

The intervention worked – at least partly. Mothers in the BLISS group breastfed longer and delayed introducing solid foods. But it had no effect on BMI z scores. In fact, more of the BLISS babies were overweight, but the difference was not statistically significant.

In addition, infants in the BLISS group were less fussy about food and enjoyed it more. Though that sounds good, those outcomes actually tend to predict a higher, not lower, risk of obesity down the road.

The Magic of Breastfeeding

Breastfeeding has many benefits. But a big reduction in the risk of obesity is not one of them. CDC has long conflated worthy goals to promote breastfeeding with obesity prevention. It’s a mistake. Facts are more durable than suppositions and myths.

More breastfeeding may lead to healthier babies. But objective evidence tells us that it will not lead to less obesity. So we need to look for other strategies that will work. And we might do well to look upstream. Both before conception and during pregnancy, a mother’s obesity can influence a child’s risk of obesity.

One might suppose that helping potential mothers with obesity could reduce the risk for their children. If so, a double benefit could result. It’s a supposition worth testing. Because suppositions aren’t good enough.

Click here for the New Zealand study and here for the companion commentary. For further perspective from Aaron Carroll in the New York Times, click here.

The Wet Nurse Angele Feeding Julie Manet, painting by Berthe Morisot / WikiArt

Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.


March 4, 2018