"“In general, exercise by itself is pretty useless for weight loss,” says Eric Ravussin, a professor at the Pennington Biomedical Research Center in Baton Rouge, La., and an expert on weight loss. It’s especially useless because people often end up consuming more calories when they exercise."

Study, have shown that if your energy expenditure and take-in is the same as dieting, exercise can produce the same results.

I have this hypothesis that it is psychologically easier to exercise off weight than to restrict your diet below maintenance.

Reason why: 1. Less willpower for exercise. Once you are on the treadmill it's easy to continue, while for dieting you will need to control yourself for at least 8hrs. So, comparing 15mins of control for getting started to exercise to 8hrs of control to diet, exercise significantly better.

2.Exercise release endorphins, ie you will be happier after exercising. Dieting leaves you irritable and tired.

3. Exercise builds metabolism, so you will burn at rest[not as much as they would have you believe in some books]. Dieting slow metabolism.

4. At moderately high intensity exercise can reduce appetite.

Drawbacks to exercise: 1) Takes alot of time. Walking at 4mph for 60mins only burns 340 calories for a 150pound man[or something like that]. So, in essence 3hrs of exercise by walk a day will burn 2 pounds a week[provided that you follow a maintenance diet]