Stoners are often characterized as pizza-eating loafs with overgrown bellies. But surprising new research out of France has found that pot smokers are actually thinner than those who don't indulge in marijuana. Here, a brief guide to this counterintuitive finding:

What did the study find?

Dr. Yann Le Strat, a psychiatrist at France's Louis-Mourier Hospital, looked at data from two studies of U.S. adults from the early 2000s and noted the weight differences between those who used cannabis and those who didn't. In both studies, cannabis users had relatively low rates of obesity: 14.3 and 17.2 percent. American adults who didn't use cannabis had obesity rates of 22 and 25.3 percent.

Is this what researchers expected?

Nope. "Cannabis is supposed to increase appetite," says Le Strat. "So we hypothesized that cannabis users would be more likely to have higher weight than non-users and be more likely to be obese." Marijuana activist Michelle Aldrich isn't all that surprised. "It's true," she says. "I don't know too many fat marijuana smokers."

What's causing this phenomenon?

"There could be many other reasons why pot smokers have less obesity," says dietitian Andrea Giancoli. "Maybe they're inclined to exercise more, be outdoors more, eat more fruits and vegetables." Aldrich thinks it could be related to the body's endocannabinoid system — a group of receptors, primarily in the brain, that respond to compounds in marijuana. But the bottom line is that the exact mechanism responsible for this correlation remains a mystery — for now.

So... sparking up isn't the new Weight Watchers?

'Fraid not. "The take-home message is certainly not 'smoke cannabis, it will help you lose weight,'" says Le Strat. "The possibility that cannabis is associated with a lower risk of obesity remains an interesting hypothesis, but certainly does not counterbalance its negative effects on health and mental health." Well, even with these inconclusive results, says Ben Yakas at Gothamist, I can't help but wonder what would happen if portly New Jersey Gov. Chris Christie "stayed away from the helicopters, fatty foods, and beaches for awhile and got in touch with his inner Snoop Dogg."

Sources: Gothamist, MSNBC, SF Weekly