It's been a few months since I read THE PALEOLITHIC PRESCRIPTION but I
don't remember Eaton referring examining this issue so directly.  As I
recall the book tended to generalize a lot and reached a number of
conclusions that Eaton himself has backed off on in the last few years
(mostly in the area of being less conservative on the issue of fat and
backing off on his claims that cereal grains are "too valuable" to give up).

The data I'm mostly familiar with (Ember CR.  Myths about hunter gatherers.
Ethnology 1978;17:439-48.) shows that for hunter/gatherers worldwide, more
than 75% of them get somewhat more than 50% of their daily calories from
animals, including insects, shellfish, and etc.

I don't think I should have implied that the !Kung are the ONLY ones on the
low end of the meat-eating spectrum or even that they are necessarily the
lowest, though their intake is pretty low compared to most.  My point was
that there are -no- pre-agricultural peoples who do not eat some meat, and
a majority of them get most of their calories from it.