Kevin Tisdel seems to believe that paleolithic man would normally walk
10-15 miles a day in search of food and shelter. I do not share his belief.
Energy expenditure must have been higher than in sedentary westerners, but
construction workers and some other manual labourers of the first half of
this century had probably a still higher level of physical activity on an
average. Nevertheless this has apparently not been dramatically protective
in terms of cardiovascular disease and diabetes among such groups [1].

As for contemporary hunter-gatherers, it is true that Australian Aborigines
had a very high level of daily physical activity [2], but those living in
most other parts of the world apparently had not. On an average they have
spent 2-3 hours per day for subsistence activities [3-7]. But the
variablity is large. On the one extreme, a female Machiguenga of the Amazon
dug up enough tubers in one hour to feed 25 adults for one day [7]. On the
other extreme we find populations living in deserts, the Arctic or similar
marginal habitats and who have spent more than seven hours a day hunting or
gathering  [3]. The very high level of physical exercise exerted by the
Tarahumara Mayans of Mexico [8] can hardly be considered representative for
traditional human populations.

1. Dorn J, Trevisan M. Physical activity and cardiovascular disease: a
review of the literature. Nutr Metab Cardiovasc Dis 1992; 2: 40-6.

2. O'Dea K. Marked improvement in carbohydrate and lipid metabolism in
diabetic Australian aborigines after temporary reversion to traditional
lifestyle. Diabetes 1984; 33:596-603.

3. Hayden B. Subsistence and ecological adaptations of modern
hunter-gatherers. In: Harding RDS, Teleki G, ed.  Omnivorous primates:
gathering and hunting in human evolution.  New York: Columbia University
Press, 1981: 344-421.

4. Sahlins M. Stone Age Economics. Chicago: Aldine, 1972

5. Taylor CB, Ho KJ. Studies on the Masai. Am J Clin Nutr 1971;
24:1291-3.

6. Lee RB. What hunters do for a living, or, how to make out on scarce
resources. In: Lee RB, DeVore I, ed.  Man the hunter.  Chicago: Aldine,
1968: 30-48.

7. Johnson A, Behrens CA. Nutritional criterioa in Machiguenga food
production decisions: a linear-programming analysis. Human Ecology 1982;
10:167-89.

8. Groom D. Cardiovascular observations on Tarahumara Indian
runners--the modern Spartans. Am Heart J 1971; 81:304-14.


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Staffan Lindeberg M.D. Ph.D. Dept of Community Health Sciences, Lund
University, Mailing address: Dr Staffan Lindeberg, Primary Health Care
Centre, Sjobo, S-22738 Sweden, +46 416 28140, Fax +46 416 18395
http://www.panix.com/~donwiss/paleodiet/sl1.shtml
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