Sounds similar to my DS. He won't eat a meal like me, but as long as he eats at least two things on his plate I'm happy. I will then offer him fruit, custard n jelly or crackers if he is still hungry.
When my son is home he seems like he's eating nearly every hour. But I think sometimes it's because he really needs water or he's bored. So try to get him to drink water & then he can have something to eat or I prolong giving him something.
I'm going to worm my son & myself tomorrow as well. We're overdue for it.