Hi there!
My 34ish kg 5 year old boy gets :
3 cups dry
250gm "Formula" which is a preservative free mix of chicken, rice, pasta, vegies, egg, cheese etc
3 or 4 chicken necks
1/2 cup of yoghurt.
He doesn't get all of this in one meal (!!) but spread over the day. He gets some dry first thing, the "Formula" in his Kongs when we go out and the rest whenever.
Doesn't sound like heaps when compared to some others but it works for him.
Oh, he also gets a tin of sardines a couple of times a week.
You will soon be able to work out if he is getting too much or not enough by his condition. I agree about finding something other than the Coles roll too!
Trish