John Cloud explains in TIME magazine why exercise alone is not the answer for weight loss.
... I have exercised like this — obsessively, a bit grimly — for years, but recently I began to wonder: Why am I doing this? Except for a two-year period at the end of an unhappy relationship — a period when I self-medicated with lots of Italian desserts — I have never been overweight. One of the most widely accepted, commonly repeated assumptions in our culture is that if you exercise, you will lose weight. But I exercise all the time, and since I ended that relationship and cut most of those desserts, my weight has returned to the same 163 lb. it has been most of my adult life. I still have gut fat that hangs over my belt when I sit. Why isn't all the exercise wiping it out? Read more