The new issue of scientific american shows that hunter gatherers expend the same amount of calories per mass as me sitting at a computer.
“But a funny thing happened on the way to the isotope ratio mass spectrometer. When the analyses came back from Baylor, the Hadza looked like everyone else. Hadza men ate and burned about 2,600 calories a day, Hadza women about 1,900 calories a day—the same as adults in the U.S. or Europe. We looked at the data every way imaginable, accounting for effects of body size, fat percentage, age and sex. No difference. How was it possible? What were we missing? What else were we getting wrong about human biology and evolution?” Part way through the article...