On the subject of calories:

For the record, I actually lost 80lbs years ago by simply cutting down on calories. I didn't exercise. I didn't really change my eating habits other than not pigging out all the damn time. I even ate a big burger or an ENTIRE medium Domino's Pizza nearly every Friday and still pulled it off. Kept the weight off for about 5-6 years too.

These days I am attempting to lose weight again, but since I am older, I actually have put a better effort towards it. So far so good (roughly 15lbs off in month and a half now).