The question addressed in this paper is whether the consumption of snacks contributes to higher energy intake and body weight in humans. Currently available snacks have a higher energy density than most of the foods that were available in Paleolithic diets. Humans have a weak defense against overeating, which is a functional trait from an evolutionary perspective. Various studies found that people do not compensate their energy intake after the consumption of snacks. This is particularly true for energy-containing drinks, which provide calories in liquid form. It is concluded that snack consumption may contribute to a positive energy balance.