I think there are subgroups of people that get caught up in certain routines they then have a hard time exiting. Drugs increase that risk but even here different people are vulnerable to different things. A good friend of mine told me with a straight face that his doctor explained to him that his BMI is in the "you are eating yourself to death" region. He told me this over refilling his glass of coca cola.

At the same time the bankster i know is still in the process of winning both capitalism and hedonism. I think it is likely more about how you manage your own weaknesses. One of them wont do this till he needs judicial/medical intervention.

edit: Never tried cocaine or heroin btw and had a rather easy time loosing weight. But i am very confident about the outcome of those two people. One has given up while the other knows he cant trust himself with this stuff, has planed and is acting accordingly and is able to grind through very unpleasant stuff.