With New Year's resolutions only a few weeks old, weight loss is on pretty much everyone's mind. Or by now you may have decided there's no hope and just devoured all that leftover Christmas chocolate!
Most of us don't yo-yo crazily back and forth from fat to skinny and from ripped to emaciated. But some people have made such behavior a way of life. Check out these 15 actors, who made dramatic - and in some cases shocking and quite unbelievable - weight changes to nail the part. We can only imagine the damage they're doing to themselves for the sake of our entertainment. And money, of course.