What is Complete Nutrition?
Complete nutrition is an intake of nutrients which keeps the body healthy. It is defined in terms of a list of substances ("essential nutrients") which must be ingested for health, minimum adequate quantities of these nutrients, and maximum tolerable quantities of these nutrients. These quantities vary from person to person.
There may be essential nutrients which have not been discovered. This would obviously pose a practical problem for consumers of complete foods, in that they could expect to begin experiencing deficiencies of an unknown nutrient! However, it is perhaps unlikely that undiscovered essential nutrients exist. The strongest evidence for this is that people have lived for years on a diet consisting only of synthetic medical food (much akin to complete foods), and not exhibited any nutrient deficiencies. In any case, the growing popularity of complete foods will certainly test this question further.
Every complete food recipe worthy of the name contains all known essential nutrients in adequate quantities. In addition, it may contain various nonessential nutrients which are, or may be, of assistance in various ways. Our purpose on this page is to discuss all of these nutrients and in particular the question of minimum and maximum intakes of each.
In answering the latter question we will follow the DRIs (Dietary Reference Intakes), which are the U.S. government's set of dietary standards. This choice is merely because nwthomas lives in the U.S., and the reader could choose to follow any other set of evidence-based dietary standards. Furthermore, we shall deviate from the DRIs where we know that demonstrably better standards are available.
There is some terminology associated with the DRI, which we must now learn. An "RDA," or "Recommended Daily Allowance" of a nutrient, is the amount of the nutrient which (it is estimated) is an adequate average daily intake for 98% of people. An "AI," or "Adequate Intake" of a nutrient, is defined when there is not sufficient data to establish an RDA, with its precise statistical definition. An AI is simply a level of average daily intake which is (estimated to be) adequate for a great majority of people. A "UL," or "Tolerable Upper Limit," is the (estimated) maximum amount which is likely to pose no risk of harm.
In summary, we want to get at least the RDA of each nutrient, or at least the AI when no RDA is defined, and we want to get no more than the UL of each nutrient.
There are some fine points to note regarding RDAs (and AIs). If a given intake level will keep 98% of people healthy, it is not only true that the amount is not enough for 2% of people; it is also true that the amount is more than enough for almost 98% of people. These "minimum amounts" are in a sense not minimum at all, in that for almost 98% of people they are more than the minimum. Thus the RDA should not really be considered a "small" or "stingy" amount of nutrient; for most people, it is actually generous.
Furthermore, a person does not need to get the RDA of every nutrient on every single day in order to maintain health. They can get less than the RDA of a nutrient on some days, and more than the RDA on other days, and as long as their average daily intake meets the RDA they will be fine. It is worth noting in this connection that the great majority of people probably fail to reach the RDAs of many nutrients in their average food intake.