He's getting a bit skinny-malinky.
Part of the problem is he gets bored of sitting to eat, though he has a goodish appetite. So meals are long drawn-out affairs. We do eat good food as well, I'm not really worried here, I just think he's a bit more waif-like than necessary.
What are good snacks, that have more protein and good stuff in than fruit, muesli bars, etc?