Researchers discovered that states with high rates of antibiotic use also tend to have higher obesity rates. The maps are striking, with the Southeast leading and the West Coast showing the lowest rates of prescription use and low obesity.
Kiera Butler and Jaeah Lee at Mother Jones report:
[Centers for Disease Control and Prevention epidemiologist and a lead author of the study on antibiotic use] Lauri Hicks and her team can’t yet explain the connection between obesity and high rates of antibiotic prescription. “There might be reasons that more obese people need antibiotics,” she says. “But it also could be that antibiotic use is leading to obesity.”
Indeed, a growing body of evidence suggests that antibiotics might be linked to weight gain. A 2012 New York University study found that antibiotic use in the first six months of life was linked with obesity later on. Another 2012 NYU study found that mice given antibiotics gained more weight than their drug-free counterparts. As my colleague Tom Philpott has noted repeatedly, livestock operations routinely dose animals with low levels of antibiotics to promote growth.
No one knows exactly how antibiotics help animals (and possibly humans) pack on the pounds, but there are some theories. One is that antibiotics change the composition of the microbiome, the community of microorganisms in your body that scientists are just beginning to understand. (For a more in-depth look at the connection between bacteria and weight loss, read Moises Velasquez-Manoff’s piece on the topic.)