find out how mush food you need to have on your plate each time you eat then put the rest away before you start eating. have your walk right after you finish your meal. don't snack,work out instead.just do it.
What, you're going to work out three times a day? And right after a meal, when you're still digesting? Not likely. Exercise will help, but obviously overeating at each meal presents potential problems other than just weight gain.