Ok so it feels like both my kids are massive eaters, they just seem to nag me all day for food

so a few weeks ago DS started school. This is his usual daily diet:

Breakfast:

Mini wheats with or without banana (depends) 1 or 2 bowls

Lunchbox:
Recess: Le snak, fruit bar, yoghurt, tiny teddies, muffin or cake or something that i've made
Lunch: Sandwich (usually ham with cream cheese and tomato)

so im looking for ideas for after school snacks. he comes home pretty hungry, and usually he will have a couple of pieces of fruit (this arvo he is having an apricot and nectarine) but i usually start cooking dinner about 5 or 5:30 (cause i get hungry Lol) and getting him to eat all his dinner is usually pretty annoying.

what are some ideas for snacks that aren't too filling? or should i just have him stick with the couple of pieces of fruit and then make him wait for dinner? that's what i usually do and even then when he's supposedly starving, he will still fuss. Grrr!!!

TIA