Oatmeal is an example of a functional food because it has soluble fiber. The fiber is beneficial for lowering cholesterol. Nuts are a functional foods, as they are high in protein and balance blood sugar. Fortified foods are also functional foods, such as orange juice that has been enhanced with calcium. Some foods, like breakfast cereals and yogurt, are fortified to make them more beneficial for the body.
According to the Mayo Clinic, fish is also a functional food, since it is high in omega-3 fatty acids, which aid in joint pain management and lower heart disease risks. Functional foods are those that have a positive impact on health beyond the foods' basic nutritional value. All foods have a level of functionality to them, however, because they provide the body with varying amounts of nutrition and energy.
Foods that are classified as functional are those that promote ideal health or prevent diseases and other unfavorable conditions. Functional foods are regulated by the Food and Drug Administration according to whether the substance is a food additive, conventional food, foods for special diets, medical food or dietary supplement. Foods that are created for specific dietary needs include infant formula and hypoallergenic foods. Even with the inclusion of functional foods, the Mayo Clinic asserts that a balanced and healthy diet is still required for optimal health.