Methodological advances now permit human biologists to more effectively monitor energy dynamics in traditional societies. This study examines the nutritional ecology and energetics of semisubsistence herders of Siberia (Evenki) during a single season of their annual cycle (late summer). Total energy expenditure (TEE) among adults, as measured by daily heart-rate monitoring, is greater in Evenki men (TEE = 11.9 ± 2.8 MJ/d in men and 8.8 ± 2.1 MJ/d in women; P < 0.001), a pattern that reflects the current division of labor under collectivized herding systems. Energy intakes are also greater among men (13.4 ± 5.6 vs. 8.5 ± 3.4 MJ/d; P < 0.01), and are, on average, sufficient to meet daily needs in both sexes. The Evenki appear to be in energy balance at the population level during the late summer (per capita energy intake = 9.0 ± 5.5 MJ/person/d; per capita requirements = 8.6 MJ/person/d); however, only small changes in food availability and/or energy expenditure are necessary to shift the population into negative balance during the winter. Primary sources of dietary energy include reindeer meat and other animal products (25-30%), foraged plant foods (10-15%), and nonlocal products (55-65%), such as flour, rice, and sugar. The anthropometric data indicate that the Evenki grow slowly and have small adult body size. Women are relatively heavier and fatter than men, and show a centripetal pattern of fat distribution. Evenki males appear to be undergoing a secular trend in stature, while no such increases are evident in females. These gender differences may reflect the differential impact to the changes associated with collectivization. Reduced metabolic requirements (due to declining activity and fertility levels), along with greater food availability, are likely to be responsible for the higher rates of obesity among Evenki women. © 1996 Wiley-Liss, Inc.
Copyright © 1996 Wiley-Liss, Inc.