How can I solve this bad eating habbit I have about finishing everything on my plate and do you do this too?

Whenever I have a meal I have this need to finish everything even if I am really full. This is bad when I order food delivered bec I try to order more to cover the cost of delivery and save for later but it's like i keep eating even though I really don't want to and feel full and not getting any pleasure out of it. I don't know why I am this way and do you know how I can change this? I am not overweight so once I stuff myself I can go on for a long time without eating but I'd rather eat twice or 3 times/day instad of finishing everything I cook or have at once!