Exercise is the motivation to eat well?

I know that diet is the biggest component when considering weight changes. But it seems that when I am exercising a lot (P90X, for example) I do really well watching what I eat.

When I fall off a regimen of exercise, I find it hard to continue to eat healthy. It's as if when I eat something, I evaluate having to burn it off in a workout, but when I'm not exercising, it doesnt' matter.


Does anyone else find it really hard to eat right without exercising? Or is it just me?