Do You Smell Fat?

If you are very overweight, your breath contains different gases than someone who weighs less. The cause: Bacteria living in an obese person’s digestive tract produce more methane and hydrogen.

“(Our research)… is the first large-scale human study to show an association between gas production and body weight — and this could prove to be another important factor in understanding one of the many causes of obesity,” says researcher Ruchi Mathur, M.D. “We’re only beginning to understand the incredibly complex communities that live inside of us. If we can understand how they affect our metabolism, we may be able to work with these microscopic communities to positively impact our health.”

Humans can’t detect methane with their noses, but breath tests in the future may be able to analyze your susceptibility to gaining weight.