Breakfast cereal (or just cereal) is a food made from processed grains that is often eaten as the first meal of the day. It is eaten hot or cold, usually mixed with milk, yogurt, or fruit. Some companies promote their products for the health benefits from eating oat-based and high-fiber cereals. In America, cereals are often fortified with vitamins. A significant proportion of cold cereals are made with high sugar content. Many breakfast cereals are produced via extrusion.