Fast food refers to food that can be prepared and served quickly. It can come from many places: sit-down restaurants, counter service, take-out, drive-thru, and delivery. Fast food is popular because the food is inexpensive, convenient, and tastes good. Fast food may include refined grains instead of whole grains, contain saturated fat, cholesterol, and added sugar, and it can be high in sodium (aka salt) which is used as a preservative and makes food more flavorful and satisfying.