>>" there is not enough direct nutritional support to feed the world"<<
There could be...
In part, the reason for this is due to the loss of the natural flora in the human gut... specifically many various species necessary for nutrient manufacture and absorption.
One need only eat a very small amount (compared to the normal North American Diet) of high quality, nutritionally dense foods in order to thrive... *IF*, they host a broad range of beneficial and commensal microflora.
I easily eat about 20 to 25% or perhaps less per day than I once did... and am more than satisfied and healthy.