He won't eat...

Okay I know I made a post a few hours ago about this but I'm concerned. My post a few hours ago was about how me and my husband are foster parents and he brought a foster child in our home will out consulting me first. My husband tried to call me but I was at work. The child is 15 and was in a mental hospital for 6 months for trying to burn down his last foster families house. They dud something traumatic to him so he did that. I told my husband he can stay but if he gets too violent he has to go.

He hasn't said anything at all and he's been here nearly 30 hours. I made dinner again and he just sat at the table and stared at his plate the whole time. I asked was he hungry. He said.nothing. He just sat there until me and my husband were.done and then he got up and went went to the guest room. Second night he didn't eat. He didn't eat breakfast or lunch either. Idek when he last ate at th Institution. Very unsure of how to get him to eat

Edit: For medication, the pills they gave us for him are abilify, Prozac, and trazodone.