All foods are functional by virtue of the nutrients they provide. While there are different definitions for the term functional foods, the overriding idea is that these foods have some ingredients or components that offer a benefit outside of nutritional value.

There are many different functional foods on the market today, grouped into four basic types: (a) naturally occurring, (b) Fortified, (c) Foods with non food additives, and (d) tailor made foods.

Naturally occurring foods are the oldest category. They are unmodified and confer a health benefit in their natural state. Fortified foods have extra added nutrients whereas, tailor-made functional foods are manufactured for a specific purpose.