This doesn't even require you to be an athlete, or do extensive physical activity. Add even a half-hour jog three days a week to your otherwise-mostly-sedentary routine and you'll tend to engage in "compensatory eating" even if you don't realize it.

This is why exercise alone often doesn't cause you to lose weight, or at least not as much as you'd expect given the extra calories you're burning: you're probably eating more (or the same amount, but foods with higher calorie density) than you were before, even if you didn't consciously choose to do so.