Undersøgelsen af Hadza-jæger-samlere viser, at deres fysiske aktivitetsniveau er højere end hos vestlændinge, men deres samlede daglige energiforbrug er ikke anderledes, når der tages højde for kropsstørrelse. Lignende metaboliske omkostninger ved gang og hvile tyder på, at energiforbruget kan være en evolutionær egenskab, der ikke er stærkt påvirket af kulturelle forskelle. Dette udfordrer nuværende modeller for fedme, der antyder, at vestlige livsstile fører til lavere energiforbrug.
Titel på undersøgelse:
Hunter-Gatherer Energetics and Human Obesity
| |
Hele abstrakt på originalsprog:
Western lifestyles differ markedly from those of our hunter-gatherer ancestors, and these differences in diet and activity level are often implicated in the global obesity pandemic. However, few physiological data for hunter-gatherer populations are available to test these models of obesity. In this study, we used the doubly-labeled water method to measure total daily energy expenditure (kCal/day) in Hadza hunter-gatherers to test whether foragers expend more energy each day than their Western counterparts. As expected, physical activity level, PAL, was greater among Hadza foragers than among Westerners. Nonetheless, average daily energy expenditure of traditional Hadza foragers was no different than that of Westerners after controlling for body size. The metabolic cost of walking (kcal kg(-1) m(-1)) and resting (kcal kg(-1) s(-1)) were also similar among Hadza and Western groups. The similarity in metabolic rates across a broad range of cultures challenges current models of obesity suggesting that Western lifestyles lead to decreased energy expenditure. We hypothesize that human daily energy expenditure may be an evolved physiological trait largely independent of cultural differences.