Functional foods are foods that have a potentially positive effect on health beyond basic nutrition. Proponents of functional foods say they promote optimal health and provide support to the body's systems to reduce the risk of disease. Generally, they have a potentially beneficial effect on health when consumed on a regular basis at certain levels.
Functional foods, as opposed to "fortified" foods, are naturally nutrient dense.
While many functional foods may also be termed superfoods, a superfood is merely a health marketing term used to describe a food with a ‘superior’ nutritional composition. A functional food is not a marketing gimmick- it is truly valuable to your health and nutrition.