I came across this article in Mother Jones – it is not available online.
Researchers looked at the demographics of the states within the USA, looking for increased antibiotic use in states like Florida (higher percentage of elderly folk). Race, education, health care coverage and income didn’t correlate with increased usage either. Only one demographic did – obesity. Fat people use more antibiotics.
Now it could be because fat people get sicker more – but so do the elderly, so do the poor. Or could it be that antibiotics add to your weight. It sounds crazy but that is why they are fed to cattle.
Hicks was surprised to find that states with higher rates of antibiotic use also were very likely to have significantly more obese people. The research team can’t yet explain the connection, and they suspect a chicken-and egg effect might be at work: “There might be reasons that more obese people need antibiotics,” she says. “But it also could be that antibiotic use is promoting weight gain.”
Meat producers have long dosed livestock with low levels of antibiotics to bulk up their animals, and recent studies suggest that the antibiotics your doc prescribes may have similar effects. A 2012 New York University study found that use of the drugs in the first six months of life correlates with obesity later in childhood. Another 2012 study from the same lab found that mice given antibiotics gained more weight than their drug free counterparts. No one knows exactly how antibiotics help animals-and perhaps humans-pack on the pounds, but some researchers think that it has to do with their effect on the gut microbiome, the intestinal community of microorganisms that scientists and doctors are just beginning to understand.