Enjoy your meal .
Eat slowly .
Chew your food well!
Give your body time to feel that you had enough.
That means: stop after having eaten a reasonable amount [not feeling very hungry any more], wait for 20 minutes [or a bit longer] ,do something else in this time and then continue if you still feel you want to eat.
You may discover that you may not need to eat any more or just a bit more to feel totally satisfied!
This waiting may ask a bit of discipline from you, according to your character, but you will feel very happy to be able to do this….and with big advantage!