Start an online journal in the women's section
You'll be held accountable by your (cyber) friends, and less likely to cheat because you know you're going to report back to them later. Also, keeping a food journal so that you can physically see how much you're eating.
To make mysel go to the gym after a long day at work/school, I remind myself of all the eye candy that will ALSO be going to the gym after a long day at work/school