This term, recently invented, was introduced
starting in 1989 by DR. Stephen De Felice.
He put together the words “nutrition” and “pharmaceutical” and thus,
created a new concept:

Natural constituents present in foods or plants could
be used to formulate plant complexes with positive effects
for health, prevention and treatment of diseases.

To be defined as “functional” these foods need
scientific evidence that proves their positive influence on a
or more physiological functions