Many cigarette smokers have shed extra pounds through their otherwise-unhealthy nicotine habit. But now, scientists have identified and isolated the pathways in the brain that are affected by nicotine's appetite suppressants. The research, published in the journal Science, might lead to the development of a healthy, nicotine-based treatment to control obesity. Here, a short guide to the findings:

How did the researchers make their discovery?
It was accidental, actually. Researchers from Yale and Baylor were looking for new drugs to treat depression, when they noticed that mice given nicotine were eating less. The scientists gave the mice a chemical compound that blocked nicotine receptors, and the rodents' appetites returned. Next, the researchers genetically modified some mice to knock out those nicotine receptors. When given nicotine, the mice without nicotine receptors did not lose weight, but mice with the receptors did. The researchers also found that these receptors are independent from those known to trigger tobacco cravings in smokers.

Does that mean nicotine can cure obesity?
Maybe. A lot of tests and studies still need to be completed. But this research suggests that it is possible to make a nicotine-based drug that isn't addictive, even though it still has nicotine's appetite-suppressing powers. 

How long until we have a nicotine diet drug?
A long time. The early trials of a such a drug on mice have gone well, but the effect of a nicotine-stimulating drug on human test subjects is still unknown. There is also a fear of side effects, such as dangerously increased blood pressure and heart rates. "No one should wait around for a new drug that might help them stay slim," says Alice Park at TIME

Sources: BBC, CBS News, Discover, Science Blog, Gamut News, TIME