I normally have all my snacks and eat every 2 - 3 hours. I think you give your metabolism a boost whenever you eat, so eating your snacks will help you burn more calories.
Also, if you don't eat your snacks you may feel hungry before your next planned snack / meal which may cause you to over-eat or eat something unplanned etc.
I think your supposed to have the snacks but I dont, I think its made my loss slower because my metabolism is not as fired up? Will try eating them this week and report my findings