NEW YORK - Anybody who's smoked marijuana knows about "the munchies," that desire to eat everything within reach. But a study from France has found that, surprisingly, pot smokers are actually less likely than non-smokers to pack on weight.

Using data covering more than 50,000 US adults, researchers headed by Yann Le Strat, a psychiatrist at the Louis-Mourier Hospital in Colombes, France, found that roughly 14 percent to 17 percent of the people reporting that they smoked pot at least three days per week were obese.

That compared with a 22 to 25 percent obesity rate among people who said they had not used pot in the past 12 months.

"Initially, we thought we made a mistake," said Le Strat, adding that he and co-author Bernard Le Foll checked the results several times to make sure they were correct.

"This is only a preliminary result. It doesn't mean that marijuana does actually help you lose weight, but perhaps there is a component that does."

The study, published in the American Journal of Epidemiology, included two surveys of US adults -- one covering 43,000 people, the other about 9,300 respondents. Both had been conducted by branches of the US National Institutes of Health between 2001 and 2009.

The larger of the surveys found that 14 percent of pot smokers were obese compared to 22 percent who didn't smoke pot. Similarly, the smaller survey found 17 percent of pot smokers to be obese compared to 25 percent of non-smokers.

Of all respondents to both surveys, between four percent and seven percent said they smoked pot at least three times a week.

Whether or not they smoked cigarettes as well had no influence on the obesity findings, though the researchers did not look at whether diet and exercise habits were different in pot smokers and non-smokers.