In our home, we have decided that eating is simply not a big deal. I think this all started with nursing my children on demand. Whenever they were hungry, even if it felt off to me (too much, too little), I obliged! When they started eating solids, it just made sense to us to keep that same attitude. I think the real question should be why is your snack food not considered worthy of a meal?
Most of the time, we eat very healthy foods and we give our son a lot of opportunities to express his wants and preferences. For example, breakfast here is generally one of 4 options: oatmeal, eggs in various forms, fruit and yogourt parfaits, or a smoothie. Sometimes we have organic cereal but we don't often have milk in the fridge, so that is very limited as well. Every morning my 3 yr old choses what he wants to eat and the quantity he eats varies greatly. Some days, he'll have 2 eggs and 2 toasts (no kidding!). Others, he won't even finish 1 egg and leaves his toast. We think of it as encouraging him to be in tune with his body, and to eat as much or as little as he feels he needs. If I think he hasn't eaten quite enough and I have the time, I offer him an all-fruit smoothie to take to daycare with him. He never turns down a smoothie LOL!
It's the same for dinner really. Some days I'll make a full sit-down dinner (like shepherd's pie with salad), some days we all snack for dinner (a plate of strawberries, cucumbers, cheese, boiled eggs, hummus, etc) when the kids are playing outside and no one wants to go in or stop to eat.
If he doesn't want to eat what we're eating, we respect that and always try to encourage him to have a taste. He never wants to at first but often comes around and has a bite, which he doesn't like. We praise him for trying and move on.
If he doesn't want to eat when we're eating, we allow him to eat later in the evening when he is hungry. At that point, we offer any of the fresh, whole food we have in the house - never junk food, rarely processed food like crackers or bread. Most of the time, he wants a piece of fruit, which I will never refuse, and try to give him a few nuts to eat along side it to regulate his blood sugar before bedtime. Besides, don't experts claim that eating smaller meals consisting of fresh, whole foods more frequently during the day is the healthiest was to eat?
I've struggled my whole life with food and food-related issues, and frankly, one of my biggest pet peeves is how much importance our society places on food. Food as a celebration, food as a reward, food as comfort, food as an activity... the list goes on and on! The dinner table doesn't have to be the end all, be all of family life!
Point is, I wouldn't worry about it. Just make sure you only offer fresh, whole foods and it will not matter when or how your child eats it!