The amount varies.
Types:
Toast with jam.
fruit.
Yogurt with granola sprinkled on it.
Sometimes ice cream or a muffin if they are in the house.
Rarely chocolate.
I am sort of a grazer, if I have a lot of time I might have free. If I am busy, I eat less.
I think the key is to recognize when you are HUNGRY, not just bored and wanting stimulation.
Research has shown that people eat more if they are watching a movie than if they are not.
I have also heard (from my MIL who read it) that research showed that a certain combination of Sugar/Salt/Fat results in overeating, and that mice or rats would overeat almost to the point of death, if given these elements together in the right proportion, in an unlimited supply. Scary. I think it must be some kind of biological instinct. I have noticed that when I eat food that has all three, it can feel like I always want more of it. If I start to catch myself eating a lot of one food, I think Sugar/Salt/Fat, and if the food has those, I stop eating, or eat something else that doesn't have all three.