American bellies coast to coast are still bulging from turkey and stuffing post-Thanksgiving. In other words, it's a lot like any other day of the year -- just add sweet-potato casserole and pumpkin pie. Eating, after all, is fun. Diets, not so much, and exercise -- let's face it -- is flat-out work. The problem with this is that a few hundred unneeded calories a day, gigantic portion sizes and years of being chained to a desk have a way of making people think the bathroom scale must be broken and that their walls are hung with fun-house mirrors. Of course, being overweight isn't simply a result of poor dietary habits and physical inactivity for everyone, because genetics can play a role, too. The good news is there are options, both for those looking to shed excess weight and for investors hoping to add some heft to their accounts. Already several medical treatments for fighting obesity are on the market or in trials, and for some people, surgery is being welcomed as a quick way to slim down after diet and exercise have failed. As obesity rates rise, and with Americans spending $33 billion a year on weight-loss measures, according to the National Institutes of Health, it's no wonder the number of firms grabbing for a share of the market seems to be growing.