Does childbirth cause obesity?
Many girls swear that it happened because of making babies, but a study of this question from April’s issue of the journal Obesity(1) shows that is just not true.
This study examined the association between parity (number of pregnancies) and long‐term weight gain in a cohort of 8,009 young women participating in the Australian Longitudinal Study on Women’s Health (ALSWH). They found, while watching these girls for more than 16 years, that there was no effect of parity on body mass index (BMI) of greater than 25 (=obesity). They found that, on average, that they all gained about 4 BMI unts. So time was probably the biggest “cause” of obesity.
However there were significant associations with having no paid job and depression. Those were associated with increased BMI. University education and high levels of physical activity were associated with smaller increases in BMI.
You know by now that calling those positive and negative associations, “effects” or “causes” of obesity or “protective” of obesity, is misbegotten. You know from my column last week, for example, that poverty, aka “no paid job” and lack of “university education,” is not a cause of obesity, but rather a result of it. Also I would have thought that chasing kids would have represented a huge “level of physical activity.”
“When all is said and done, it’s biological susceptibility that sets a person up. You don’t choose it, you inherit it. And then life events and a person’s environment provide triggers. Some people in the same circumstances might be resistant. It’s not a matter of choice.”(2)
At any rate, there might be lots of good reasons for birth control, but it is pretty safe to say that preventing obesity, in mothers at least, is not one of them.
1. Davis WJ et al. Long‐Term Weight Gain and Risk of Overweight in Parous and Nulliparous Women. Obesity April 2018 https://doi.org/10.1002/oby.22174
John DiTraglia, M.D., is a pediatrician in Portsmouth. He can be reached by email at firstname.lastname@example.org or call 740-354-6605.