That strikes me as a specious use of historicism since it's entirely
speculative, not in the least evidential based. Worse still, it ignores
emerging understanding of human physiology. Some amount of high fiber carbs
make the engine run at optimum, especially that large gland we call the
brain.

Wm writes:
It might have been in the Book "Searching for Dilmun", but whatever,
archaeologists have identified ancient cultures in Mesopotamia by the
style of their pottery, which remains unchanged for many generations,
until they are conquered.
These cultures were probably both meat deficient and high carb, and I
suggest that this explains their lack of invention or genius.
For a comparison, note the relative inventiveness and change in
manufactured articles of recent meat eating culture.

It could then be considered that healthy brain function requires absence
of carbs.

William