Well, I don't know your stats or your eating habits already, but perhaps you're just used to over-eating? The stomach stretches when we get full, thus leading us to be able to handle more food in one sitting. Let your stomach shrink and eat 5 or 6 smaller meals a day instead of just 3 main meals. Avoid sugar because it doesn't give you energy for very long and sends your insulin levels out of whack, meaning you'll get hungry quickly afterwards. I'm sure some other posters can be more helpful...