Ridley:
See if there are any predictable patterns you can interrupt.

http://www.malesurvivor.org/ArchivedPages/singer2.html

Since you have the discipline to do the running and crunches, you can also put this one of a track for controlling. It will be difficult because there are some rewards associated with the behavior. But for many of us the choice between a Snickers bar and doing physical activity is not complicated. Sounds like you have willpower. That will help.