lots...
Keep v v v busy...to the pace tht u dnt have time to eat.
Drink more water, Fills you up more.
Eat rice a lot. It's good for u, not fatening & FILLING!! snack on some rice & rice cakes when u feel youve ate loads and loads.
Try finding other things that makes you happy, other thn eating...perhaps take up more extra hobbys or activities that will satisfy you more than oral gratification...
I studyed psychology and a big believer of Sigmund freuds theory perhaps you eat so much as you lacked oral satisfaction as a child. Whats my point you may be thinking? Yawn! Yawn...well if my above methods fail or have been tried..why not ask ur GP for a Cognitive/behavioural psychologist...They see you in 6 sessions, its free on the nhs and what they will do is change your behaviour and thinking...see whenever you feel happy or sad regardless you eat. So they help you change your cognitive thinking and your behaviour. This is just a suggestion however! But i'd certainly give it a bash!
xxx