On Wed, 31 Jan 2001, Amadeus Schmidt wrote:

> This, and also many of his tests remind me of my "wrong carbohydrate"
> idea. Why should man not be able to digest carbohydrates well?

I think we do digest them well.  The trouble is, as you've
pointed out, to get enough energy from *paleo* carbohydrate
sources one has to consume immense quantities of vegetation.
Even to get Lutz's 72g you would have to eat about a pound of
low-density vegetables (see "frozen mixed vegetables" at USDA).
As you have argued, tubers are a better energy source, but I am
not sure how continuously available they would have been.

> The evolutionary aspect i see very weak, there are very few times in history
> of low carbohydrates. You mention that the last evolutionary times are more
> deciding. So, the last 6-10000 years should be most deciding.

No, here I have to disagree.  I do think that the more recent
adaptations are the ones that matter, but the key is adaptation,
not just time.  What forces adaptation is increased selection
pressure, and that means an increased death rate and population
shrinkage.  The environment changes and kills off many, except
for those who happen to be able to tolerate the change.  That's
selection pressure.  This doesn't apply to the last 10,000 years
of agriculture because this has been a period of population
*growth*, fueled by cheap calories.  Even if the death rate
increased, the birth rate clearly increased even more.

In contrast, during glacial maxima, those who did poorly on a
lowcarb diet perished.  The survivors were those who did well.  I
think this is why lowcarb diets help so many people, even though
most other primates do not have lowcarb natural diets.  As you've
often pointed out, the natural primate diet is high volume and
high carbohydrate.  I agree. (This, incidentally, is the model of
the _Natural Eating_ diet, by Geoff Bond.  Although Ray Audette
sometimes likes to recommend a "primate diet", Bond actually
takes it to the limit)  In my view, hominid history from Homo
Rudolfensis (2.5 mya) to Homo Sapiens has been a story of
increasing use of and adaptation to animal food, as well as
tool-based methods of food procurement and processing.

> Except if there's a reason why we are unable to digest "modern"
> carbohydrates like sugar.
> So far i found B-vitamins coenzymes and enzymes as a striking reason,
> particularly the pyruvate dehydrogenase. It's usually low in supply and
> betrays only carbohydrate.
> Other reasons may be found in other molecules, which are extracted away in
> the "refinement" process.

I agree with all of this.

> >I think what you have established is that the "mostly wild game"
> >diet was not available in certain environments.  I think you also
> >concede that it *was* dominant in certain other environments
> >(cooler, wetter).  What is not yet established is which sort of
> >environment has driven the dietary adaptations of modern humans.
>
> Yes.
> However a low-carb- diet seems to be equally seldom as a high carb diet like
> today (SAD).

It's very hard to say.  Really, what we need is a record of when
human population bottlenecks occurred, and in what environments.

> I don't think it was ever difficult to be vegetarian, i think people didn't
> try to avoid it, just did seldom care about.

I disagree.  Again, I'm thinking of Weston Price's finding that
populations that seemingly could have been vegetarian went to
great lengths to obtain animal foods.  I think the evidence
suggests that human populations have *always* tried to avoid
vegetarianism.

Todd Moody
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