It would seem, at least in my superficial reading, that perhaps Dr.
Livingstone has misinterpreted the question (through no fault of his own)
to be about whether humans are omnivores or carnivores.  Yet I do not think
that anyone now seriously believes that humans evolved as anything other
than omnivores with a taste for a wide variety of foods.

This may point out to a language difficulty.  I have frequently seen Barry
Sears' THE ZONE diet, which uses 40% carbohydrate, referred to as
"low-carbohydrate." This absurdly lumps it in with other diets of less than
10% carbohydrate.  On the other hand, the current dietary fashion in
America is to that the ideal diet is 65% carbohydrate.  This would be quite
high by some standards but is normal, and perhaps even a little bit low by
others (e.g. the rural Chinese).

I think we need to either standardize on phrasing (e.g. "moderately low
carbohydrate" vs. "extremely low carbohydrate") that is intuitively
understandable, or try to stick more to numbers.

I wish we could get Boyd Eaton to join us, as he seems to have done an
awful lot of work in this department.