Beyond personal causes like metabolism or diet, there've been some fascinating discussions here in the past few months about why technologically advanced societies seem to have an exponential obesity problem starting around 1980, relative to other cultures that exercise less and take in more calories. I can't find the thread. But it definitely bears consideration. I think the view would be that hacking your way partially out of a problem isn't necessarily bad, but we've seen decades of data used to incorrectly imply one chain of causality or another and there's a larger problem to solve than a drug or a tummy tuck can tackle.