>> Hmmm, I've been contemplating this for a day or two.  According to Cordain
>> and others, up to 1/3 of the h/g diet was carbs in the form of fruits &

The number usually mentioned is 65 % animal food (wich leaves 1/3 + for
vegetables - mostly carbos). It is derived from "The Ethnographic Atlas"
(Murdoch 1967) which has a collection of statistics based on most known
anthropological site research, of wich some is quite old (from the time
when there were more h/g's around). 65 % animal food is the mean all around
the world, so if more reearch was done on inuit people than on others,
the number will have a slant upwards. The variation is, if I remember right
from 35 % (!Kung, who have a lot of nuts to eat) to something very high
(inuit). All this data is probably by weight.
In "Hunters And Gatherers of the Sea" (in Ingold, Richies, Woodburn;
"Hunters and Gatherers") Gísli Pálsson has calculated the relative
dependance on hunting, fishing and gathering among the 220 cultures in
"The Ethnographic Atlas" that rely on agriculture and/or animal husbandry
to less than 6 %. The numbers he gets are respective 28, 38 and 34 %.
So the number 65% animal food is in fact mostly fish. But the 1/3 carbos
is conformed by his data.
Remember: all this data is from recent hunter/gatherers, not paleolithic.

- Hans