I had to unschool my 4 year old yesterday. The kindergarden people had told one of the kids (not my kid) that he should finish his food. But instead of giving a sane explanation (like..we shouldnt throw away food simply because wasting food is bad and disrespectful against the plant/animal and the peope who spent time to manufacture the food) they shamed the child. They said; "Think about african kids. They don't have any food!"
Wow friend, it's a shame you had to unschool your son. I remember that the same thing about Africans without food was something they repeated constantly when we were children, and that has a negative effect on people, it is very good that you have taken that responsibility away from your child.