Don Matesz wrote
> A major problem with prescribing dietary ratios using percentage of
calories
> is that meat and fat are up to 45 times more calorically dense than
> vegetables and fruits.
>

This is a good point, particularly as it tends to refute Cordain's ratios.
While our ancestors may have eaten sufficient plant material to supply
35-55% of their calories from plant foods before the advent of the Ice Ages,
there is no way they could have done so during them. With long cold winters
and short cool summers, for most of the year there would have been very
little plant material to eat. Thus I do not accept Cordain's ratios during
the last 2.5 million years. And that is the time when 99.9% of our present
genetic makeup would have been formed.

>
> Percent mass from meat and fat = 28%
> Percent mass from plants = 72%
>

While there would have been regional differences in climate and food supply,
which today are expressed in racial differences in patterns of such diseases
as obesity, diabetes and coronary heart disease, these could not have been
as great as to have provided such a large proportion of plant material to
constitute 72% mass during the Ice Ages, even if a hominid stomach was able
to hold such a large volume, which I doubt. And even if such uncooked
material could have been digested. We have no dietary enzymes or
micro-organisms that will do the job today. If we had them then, why don't
we now?

No, under these circumstances, I believe that ratios based on Cordain's
hypotheses are unreliable and untenable.

Barry Groves
http://www.second-opinions.co.uk