From CBS News:
You may have heard that marijuana smokers get hungry after using the drug, and the authors of a new study point out that marijuana users tend to take in more calories than their counterparts. But, their study found that pot smokers aren't any more likely to be obese than non-smokers.
Equally surprising, the researchers found marijuana may actually be a tool in controlling blood sugar -- and may be key in helping diabetics keep their condition in check.
The new study, which was published on May 15 in The American Journal of Medicine, showed that regular marijuana use was linked to significantly lower levels of fasting insulin. Smokers were also less likely to be insulin resistant, a condition where the body's cells no longer respond to a hormone that controls carbohydrates and fat metabolism called insulin. High levels of fasting insulin and insulin resistance could lead to diabetes...
Keep in mind however that despite even with the benefits laid out here, marijuana use has also been linked to strokes in young adults and testicular cancer in young men. Like almost anything in the world of medicine, the risks have to be weighed alongside the benefits.