Hunter-gatherer energetics and human obesity.
Level 4 - case-series / case-control
Cross-sectional comparative physiological study between population groups
PubMed 22848382 · doi:10.1371/journal.pone.0040503
What was done
Total daily energy expenditure was measured in Hadza hunter-gatherers using the doubly-labeled water method to test whether foragers expend more energy daily than Western populations. Physical activity level, resting metabolic rate (kcal kg^-1 s^-1), and the metabolic cost of walking (kcal kg^-1 m^-1) were also compared between groups.
What was found
No numerical values are reported in the abstract. Physical activity level was higher in Hadza foragers than in Westerners. After controlling for body size, average daily energy expenditure did not differ between Hadza foragers and Westerners. Metabolic costs of walking and resting were also similar between groups.
Why it matters
This study challenges the standard assumption that Western lifestyles drive obesity primarily via lower daily energy expenditure, pointing instead to human energy expenditure being a constrained, evolved physiological trait.
Limits
The abstract does not state the sample size (n), participant demographics, or exact numerical estimates and variance. It is a cross-sectional comparative study, precluding longitudinal causal inference.
Cited by
- supports A Duke University study found that the daily energy expenditure of Hadza hunter-gatherers was virtually identical to that of sedentary desk workers.