I have noticed a really nice side benefit of being much more active....you can eat A LOT and it will have much less effect on your weight if you exercise regularly.
I have become very healthy and active over the past couple of year after peaking at 320lbs I now at around 195lbs. Of course on a daily basis I eat much better and healthier day in and day out....but I still can eat pretty darn unheathily from time to time, but it seems to have little effect on my weight now.
I attribute it to being way more active then I use to be. I have heard from others this is the case as well. So it is kind of a paradox, people who are overweight and don't workout much suffer the most from overeating, whereas active people can probably do it once in awhile with few ill effects. Ah well, in the end I guess this is simply one more potential reason to exercise. Of course feeling great and being healthy is more then enough reward that anyone could aspire to for exercising but this is a nice little benefit as well.