Actually, from a metabolic standpoint, I see obesity as a symptom of either a pre-diabetic condition, or diabetes itself - not the other way around.
In a situation where the majority of food available is high in sugars, the body learns to process and store them more efficiently. So you get a lot more insulin production, funky lipid profiles, etc... Until your body's biological insulin factory blows a gasket, and you either die, or the doctor puts you on a substitute.
I'll wager (nobody knows at the present) that it's going to turn out to be a genetic condition also... If you are in a "normal diet" environment, you may get a trifle pudgy, etc., but if you're in a "mac & cheese every night" environment, where you also run into "feast or famine" situations where the body has no idea when it's going to get fed again, you're gonna have problems.
FWIW, there's a LOT of research into the concept of continuing treatments, but very little toward a cure - not a lot of money in people who don't need meds... And most of the "public" R&D money is going toward political diseases, like HIV or breast cancer.
