10pm is second dinner

So we have family dinner time at 6/6:30 daily we all sit at the table. J can literally finish his food in under two minutes if he makes his plate by the time the next person is at the table he’s done and getting up. I had to gently remind him that we all sit together for dinner time and even if he finished early he can stay a bit. 
He doesn’t eat much during the day but around 10pm he has what I refer to as second dinner in which he eats either 3 bowls of cereal with milk, 2 packs of pop tarts or Ramen noodles. I know it’s not healthy but he is hungry and we don’t want him to go hungry. 
Lesson here for those that are not trauma informed. Kiddos from care often come with food issues. I don’t know why my kiddo wants to eat so late. I think it’s when his adhd meds which prob make him not very hungry wear off or maybe it’s a teenage boy thing. But food can help to bond and it’s best to not say no when they ask for food.