It's funny, some kids this age seem as if they couldn't care less about food, and some are just getting good and hungry! I say that if he's asking for food and is hungry, give him some food. And if he's thirsty, give him some water! Toddlers' tummies are so small that they don't hold much at one time and empty pretty quickly, so your little guy needs more snacks than we do. If you're offering healthy snacks like whole grains, dairy, and fruits and veggies, I see no problem with him snacking, as long as he still eats his meals, which it sounds like he is. He might be getting ready to have a growth spurt and just needs the extra calories now. I believe that Mother Nature was wise when she designed baby and toddler appetites. They know when they need to eat, and how much. So let him eat!