K.M.
I'm probably an oddball here. But I think snacks are fine (in between meals)as long as they are things like apples, 7 grain crackers, nuts, cheese, etc - meaning that they are healthy and hearty enough that if my daughter isnt hungry at dinner/lunch, I don't feel as if she missed out on a meal.
Personally, I am a grazer, eat when I'm hungry and allow my daughter to do the same. So if my daughter isn't hungry when we are, she can eat later or not. She's in the 50% of weight for her age. Most people need to have a more set schedule, but I work from home and she's not yet in pre-school, so it's fine.
I think either way you do it, they will be great! It's what works for YOU as the mom!