Nutritional biodiversity is a diet that focuses on the diversity of an organism's nutritional consumption or intake. Some believe this diversity directly relates to the overall health and vitality of the organism — human or animal.
Although traditional diets emphasize a sufficient intake of fruit and vegetables, they do not emphasize the range or variety of this intake. Nutritional biodiversity encourages the consumption of about 10 – 15 different green vegetables over a period of a fortnight, rather than the same green vegetable every day for that same period. This extends to all types of fruits and vegetables.
Different fruits and vegetables provide different vitamins and minerals and in differing quantities, and it is this diversity that is essential to ensure that all nutritional needs are met. It does not require one to consume all types, but to at least have sufficient variety or diversity to reasonably allow for most vitamins and minerals to be consumed.
In the book Back from the Brink, an example is used of the various bloodlines of race horses in the UK and USA. What the author found is that when horses grazed in fields that did not have weeds and had other non-grassy plants removed (hence a lower level of biodiversity), these bloodlines appeared to under-perform when compared to those that had been allowed to graze from fields in which other plants and weeds were allowed to grow freely.