Fast food refers to food that can be prepared and served quickly. Fast food restaurants usually have a walk up counter and/or drive-thru window where you order and pick up your food without having to wait long. They’re popular because they serve filling foods that taste good and don’t cost a lot of money. However, the food is often made with cheaper ingredients such as high fat meat, refined grains, and added sugar and fats, instead of nutritious ingredients such as lean meats, whole grains, fresh fruits, and vegetables.