Psychologically, as opposed to biochemically, some experts theorize that exercise might lead people to believe they can reward themselves with treats afterward or that they may be tempted to be less active for the rest of the day. And some studies, says Evans, do suggest that if you exercise, say, for 40 minutes a day, you will "then compensate by decreasing how active you are at other times of the day, leaving total energy expenditure unchanged" or that you might reward yourself with food. But other studies say both of those theories are wrong.
Take your time
What we should be focusing on is eating slowly, which does control intake. "It takes about 20 minutes for food to get digested and formulated into hormones for your brain to know what you did, to get that signal to the brain," says Blackburn. If you wolf your food, you'll finish your second helping before your brain has registered your first.