Hunter-gatherers are lean and walk 8–15 km per day. You'd expect them to burn a lot more calories than Westerners, but they don't. A landmark study found that Hadza hunter-gatherers have roughly the same daily energy expenditure as Westerners after adjusting for body size. One reason is that despite walking a lot, they also rest a lot. The Hadza aren't less sedentary than Westerners - they break up their sitting with more frequent movement. Another reason is the constrained energy expenditure model - the body adapts to high physical activity and starts burning fewer calories for the same activity. Study: PMID: 22848382

@siimland They don't eat Moon Pies.