The difference between functional food and dietary supplements is fairly easy to determine when you are aware of what the are.
First, to explain, we are all aware that food serves a basic function, and that is to sustain life for all of us.
A functional food is an ordinary, normal, everyday food that has either added nutrition or some type of health additive. So whether you are talking about whole foods, enhanced foods, or enhanced foods, these foods would need to have a potential effect that might be beneficial on health if it is consumed regularly at their effective levels.
Some examples might be iodized salt, orange juice that has calcium added, or enriched bread.
As for nutraceuticals, they are simply functional foods that have dietary supplements added. Dietary supplements, according to the Dietary Supplement Health and Education Act of 1994, are
“a product (other than tobacco) that is intended to supplement the diet, which contains one or more of the following dietary ingredients—a vitamin, a mineral, an herb or other botanical, an amino acid extract, a dietary substance to supplement the diet by increasing the total daily intake, or a concentrate, metabolite, constituent, extract, or combinations of these ingredients; is ingested in pill, capsule, tablet, or liquid form; is not represented for use as a conventional food or as the sole item of a meal or diet; and is labeled as a ‘dietary supplement.’”
So nutraceuticals are any whole food that has been repackaged and concentrated into something that is not a typical format for food, such as a capsule. A perfect example would be the food capsules you often see in the grocery store, such as Red Beet Root powder capsules, or any other similar product. Ingesting these nutraceuticals has previously shown great results in preventing diseases and improving health.