[T]he act of eating is not the only source of gustatory pleasure. Instead, a big chunk part of our sensory delight -- the joy that makes us crave particular foods -- comes afterwards, when the food is winding its way through the gut. […]
We are so convinced that the tongue is the source of culinary joy -- we eat too much ice cream because we want to make our mouth happy -- but it's not. Instead, we eat calorically dense foods because we are also trying to pleasure this secondary pathway, which responds not to the nuances of flavor but to the brute intake of energy.