when i was in college, i used to have a food card where i can deposit money and use it at any cafeteria at school for food and drinks. i used to put like $500 in the card, and i just liked to use it all, then realized the amount of weight i was getting, i stopped putting so much $ in the card as a way to force myself stop eating as much and be more considerate of what i eat. and it works!!

another suggestion is that, after a meal, don't go straight to dorm or a class, go do something (not necessary the gym) but at least you can start the calories on doing some burn down rather down just staying around the belly.