How Does Breastfeeding Protect Against Obesity?

Breast is best, when women are able to breast feed – we know this without a doubt. Infants who are breastfed enjoy a long list of health benefits, including a reduced risk of infections, autoimmune diseases, SIDS, leukemia, and more.

Breastfeeding reduces the risk of obesity as well – the available data on this suggests that there is a 15-30% reduction in adolescent and adult obesity rates if any breastfeeding occurred in infancy, compared with no breastfeeding. With the reduction in obesity risk comes a 40% decreased risk of the child developing type 2 diabetes later in life as well.

So, how does breastfeeding protect against developing obesity later in life? Well, there are a number of hypotheses. For one, when a baby is breastfeeding, the amount of milk s/he takes in is self regulated. Simply put: when they are full, they stop drinking. When a baby is bottle fed, there may be a push for baby to finish the bottle – possibly resulting in the baby taking in more food than s/he otherwise would have. Thus, with breastfeeding, the baby’s brain is programmed to self regulate how much s/he wants to eat – programming that is likely carried on with them later in life.

Secondly, the gut bacteria that the baby develops may be influenced by whether the baby is breast or bottle fed. We now know that the type of gut bacteria we carry can have a significant impact on the risk of obesity and metabolic disease such as diabetes. Also, if a baby needs to take antibiotics, this can change the bacteria in his/her gut and may affect the risk of obesity. Breastfed
infants have a markedly lower risk of respiratory and gastrointestinal tract infection, portending a lower risk of needing antibiotics as well.

Thirdly, what the baby is being fed is of course different. While every effort has been made to make infant formula as close to human milk as possible, there are many differences, with many factors unique to human milk that may affect nutritional status, energy balance and/or satiety.

Still so much we need to research, learn, and understand about this fascinating area!

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