I struggle with leaving plate on my food and I also struggle with my weight. Growing up we weren't allowed to leave food on the plate. To this day I still feel guilty for leaving food on a plate and yet I am overweight.
I know the answer is to dish out a little and get seconds if need be. Problem is I live with people who do more cooking than I do and because I am a fairly big guy they can't help but dish out massive quantities of food.