Since going back to school in September DS (16) has fallen into pattern of often not eating through the day until dinner time. He then eats a normal evening meal and generally a pudding (which might be fruit and yogurt or something more substantial like crumble and custard). Some days that's all he eats. Other days he might come foraging for food later at night (10pm onwards). Other days he might also have a bowl of cereal when he gets in from school. Very occasionally he'll get up early (say 5am) and go and eat some cereal or toast before going back to bed. He will sometimes have a milkshake or a snack at school or buy himself sweets on the way home, but that's probably less than half the time.
At weekends he tends to get up late. If someone else makes him lunch he'll eat lunch as well as dinner. Otherwise much the same pattern.
In response to questioning he says he is not eating because he's not hungry. And he often eats when food is put in front of him just because it's there. He tells me he's not bothered about his weight and to my eyes he is very skinny (but a lot of his friends are as well; I don't think he is unusually so).
He tells me that school (he's in the sixth form attached to his previous school) is "fine"; he seems to be making friends with some of the new people as well as keeping up with old friends, so no particular worries raised there. He is involved in some friendship drama, but that's been ongoing for months, so wouldn't see as a new source of stress.
I would suspect he's not eating as much as a boy his age should do, but it's hard to judge. But even if he is, this doesn't feel like a particular healthy way to eat.
Has anyone else experienced similar with their teens? Do I just leave him to it or should I actively start putting more food in front of him to see if he'll eat it (currently in our house everyone gets their own breakfast and lunch and we eat dinner together)?