"Toddlers need snacks, they can't eat enough at meal times to keep up with their needs." This isn't true, not for all toddlers anyway. When my dd1 was 18 months - 3 she needed to eat meals at the right time, but could only eat meals. If we were going to be out over lunchtime, I would pack the lunch rather than make her wait an hour, but I would give her the real food she would have had at home, like a cheese sandwich, because if I gave her some stupid cereal bar that would be it, she would have eaten, and only eaten crap. Then she would have fruit in the afternoon if she asked for it, usually didn't, and eat dinner, unless some eejit had given her a crap cereal bar, in which case, again, that would be it.
"I eat little and often, so do my kids. We're all pretty active and slim." well there you are then, if you dont' have a problem with putting weight on, this is why you don't see that snacks are EVIL (only half joking). My friends who carry cereal bars around are naturally slim too. I am not, carbs make me blimp out. I need to be very careful to stay slim, eat only whole foods and little or no sugar, enough protein, and basically almost nothing that comes in a packet - so meals, basically, not snacks. I don't want my children to think that carb-grazing is a human right, because if they are like me, it will make them miserable - either because they have to curtail something that feels socially normal, and that has become a habit; or because they will put weight on.