I am a bit confused about the whole carbohydrate issue. It appears that most
hunter-gatherers utilised some form of concentrated carbohydrate, whether it
be yams, seeds, rootstarch or whatever. (The arctic peoples used fat as an
alternative since carbohydrate was scarce, as did the people of Pacific
Northwest America).
There seem to be four reasons for including carbohydrate resources in the
human diet. One is to counteract (offset might be a better word) high levels
of protein from animal resources (if animal resources are abundant).  The
second reason is to spare protein from being converted into energy which is
an inefficient process and deprives the body of protein for maintenance and
repair (Vayda 1987, Speth and Spielmann 1983). The third reason is that the
brain uses glucos
e from carbohydrate preferentially over other foods.  The
final reason is to provide calories in the absence of animal resources by
which I mean that if other food resources are unavailable (e.g. mammals,
fish, insects etc)people will concentrate on supplying their energy needs
from carbs.

It seems to me that if the brain uses carbohydrate preferentially then the
Inuit are operating (successfully) on an inefficient process . I've
forgotten the process but i believe there is another way of feeding the
brain if they lack carbohydrate in their diet.  If there is a limit to the
amount of protein we can consume, and if wild animals in the temperate
regions contain low percentages of fat, then it would seem that we would
have to consume fairly rich carbohydrates (concentrated?)in order to live
healthily. Gould (1966), for example, observed that a 97-lb (44kg) kangaroo
yielded only 4 ounces (114g 9 of removable fat. Eating animals like this
would surely lead to protein toxicity given the imbalance of protein to fat
in the absence of carbohydrate. Fruit and vegetables provide carbohydrate,
and so do tubers, grains, and a variety of nut seed resources.  However,
since all the Australian Aboriginal groups I have looked at have utilised
one or more staples that are basically a starch food, can anyone explain to
me why the use of these concentrated carbohydrates was so widespread?.
Especially when the palaeodiet that is generally proposed on this list seems
to be low in these types of carbohydrate.

Also, since their appears to be a high prevalence for fat amongst
hunter-gatherers does that mean that we have an evolutionary need to eat
higher levels of fat or does it reflect the lack of fat in the
environment in temperate/tropical regions? We seem to have been hardwired
for sweetness hence an interest in f
ruit, honey etc but fat is not sweet.
Carbohydrates, although not tasting sweet convert fairly readily to sugars I
believe.  Might that be a reason for the widespread use of them, if they
fulfill some sort of sweetness criteria?

Or, is the consumption of starchy carbohydrates simply the result of human
groups requiring more and more energy due to population increases,
environmental changes or whatever, and having to turn to starchy carbs as a
necessity to maintain their energy requirements.  After all, many of the
carbs used by hunter-gatherers require large amounts of manual labour to
separate the starch from the plant or to rid the starch of toxins or
both.Which brings up the question of 'Why bother' unless you had to?

I would really appreciate any feedback that might clear up my confusion on
these issues.

Thanks

Sean McBride
University of Queensland

Gould, R. A.
(1981). Food sharing in Australia and California. Omnivorous
Primates:Gathering and Hunting in Human Evolution. R. S. O. Harding and G.
Teleki. New York, Columbia University Press.

Speth, J. K. and K. R. Spielmann (1983). “Energy source, protein metabolism,
and hunter-gatherer subsistence strategies.” Journal of Anthropological
Archaeology 2(1): 1-31.

Vayda, A. P. (1987). “Explaining what people eat: A review article.” Human
Ecology 15(4): 493-510.