Functional foods are foods that have a potentially positive effect on health beyond basic nutrition. Oatmeal is a familiar example of a functional food because it naturally contains soluble fiber that can help lower cholesterol levels. Some foods are modified to have health benefits. An example is orange juice that's been fortified with calcium for bone health.
Of course, all foods are functional because they provide varying amounts of nutrients and energy to sustain growth or support vital processes. However, functional foods are generally considered to offer additional benefits that may reduce the risk of disease or promote optimal health.
Currently no legal definition exists for functional foods. The Food and Drug Administration (FDA) regulates claims that manufacturers make about functional foods' nutrient content and effects on disease, health or body function. The FDA regulates these types of foods according to whether a food is considered to be a conventional food, a food additive, a dietary supplement, a medical food or a food for special dietary use.
If you want to try functional foods, choose wisely. And keep in mind that while functional foods may help promote wellness, they can't make up for poor eating habits. Your best bet is still to eat a balanced and varied diet.