To me a snack is a small low calorie meal or “snack foods” and it can be two distinct things. Some examples of a snack would be a piece of fruit, toast, boiled egg, some raw veggies, just to name a few. If can also be snack food, like potato chips, pretzels, and cheese, but those things can add up to be a lot of calories pretty fast and be more equivalent to a regular meal in the end if you eat too much of it. I think snacks should be less than 300 calories for the average person.