C-Sections Don’t Make Kids Fat

Eyebrows arched late last year when research published in the American Journal of Clinical Nutrition linked childhood obesity to being born by cesarean section. Scientists used those findings to theorize that not being exposed to certain bacteria during the voyage through the birth canal could cause kids’ immune systems to develop in ways that cause them to become overweight. Since so many American kids—30 percent—are being born via C-sections these days, researchers thought perhaps they were onto a piece of the childhood-obesity puzzle.

Not so fast.

A new review of the previous Brazilian research has shown that its authors failed to take into consideration such factors as family income, birth weight and the mother’s weight. Once those factors were accounted for, “the relationship between obesity and cesarean sections disappears,” according to Fernando Barros, who reanalyzed the data with a colleague. Barros said while there are other risks to cesarean sections, and that women should try to avoid those that are medically unnecessary, they won’t cause your offspring to be fat.