My 2 year old son won't eat if he's not home.

My son is a little over 2 and won't eat unless he is at home or at his grandmas. It's been like this for about 6 months. But yesterday with it being thanksgiving, I was hoping the mass amount of people eating around him would encourage him to eat. But nothing!! Has anyone had this issue with their little ones? How long did it last?! He throws a fit if I even ask him if he wants to eat when we are out.. I don't know what to do.