As I understand, pre-agricultural man was taller than modern man. I
understand that the transition to agriculture is largely responsible for
this, with the three important factors being: 1) the mineral blocking
effects of the phytates in grains; 2) the decrease in animal protein and
bone building vitamins A and D that are found in animal fats; and 3)
decrease in calories consumed per person as the population grew (including
periodic famine due to lack of reliable harvests).
In the last 100 years, at least in Western societies, we have recovered
much of that height. Why?
1) Are we eating more or less animal protein than 100 years ago? Mary Enig
and Sally Fallon assert that we are eating LESS animal FATS; is the
opposite true for animal protein, i.e., are we eati
ng more lean beef  and
chicken and cooking less and less with butter and lard?
2) Is the increase in height due to the refinement of our grains, which
strips them of their phytate content? If so, what does this say about
recommendations that we eat more whole grain products?
3) Is the increase in height due to the hormones injected into animals, as
many vegetarians have suggested? Is there evidence that these hormones are
present in sufficient amounts in store bought meat to have a physiological
effect? Do these hormones survive the digestion process? My understanding
was that hormones are proteins, and like most proteins, they are broken
down into their constituent amino acids during the digestion process. How
then can they have an effect on humans? Do they slip through the gut wall?
Aren't these "leaks"  in the gut wall due to ingestion of whole grains? Is
it not true that these hormones would h
ave to be COMPLETELY undigested,
i.e., if part of their structure had been cleaved off, they would not bind
to the receptor site?
4) In "African Exodus", Chris Stringer and Robin McKie state that human
height has decreased steadily over the last 10,000 years. In places where
agriculture was adopted, there was a dramatic drop off, but in other
places, there was still a dropoff, albeit a more gradual one. For example,
the average height of Australian Aboriginee males has decreased from 5'10"
to 5'6" in the last 10,000 years, despite lack of contact with agriculture.
Is this due to the change in lifestyle and eating patterns that has
occurred in the last 10,000 years due to the last Pleistoceine extinction?
Could there have been a dropoff in animal foods and a decline in calories
in general in the last 10,000 years amongst hunter-gatherers that accounts
for this decline in stature and robust
icity? In Nutrition and Physical
Degeneration, Weston Price states that for those aborigines living in the
areas of the most abundant animal foods, particularly sea foods, "their
stature was large and well formed".