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Energy expenditure and activity among Hadza hunter‐gatherers
Author(s) -
Pontzer Herman,
Raichlen David A.,
Wood Brian M.,
Emery Thompson Melissa,
Racette Susan B.,
Mabulla Audax Z.P.,
Marlowe Frank W.
Publication year - 2015
Publication title -
american journal of human biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.559
H-Index - 81
eISSN - 1520-6300
pISSN - 1042-0533
DOI - 10.1002/ajhb.22711
Subject(s) - energy expenditure , doubly labeled water , physical activity , hum , demography , psychology , medicine , physical therapy , endocrinology , art , sociology , performance art , art history
Objectives Studies of total energy expenditure, (TEE; kcal/day) among traditional populations have challenged current models relating habitual physical activity to daily energy requirements. Here, we examine the relationship between physical activity and TEE among traditional Hadza hunter‐gatherers living in northern Tanzania. Methods Hadza adults were studied at two camps, with minimal intervention so as to monitor energy expenditure and activity during normal daily life. We measured daily walking distance and walking speed using wearable GPS units for 41 adults. For a subset of 30 adults, we measured TEE using doubly labeled water, three indices of work load (foraging return rate, maternal status, and number of dependent children), and urinary biomarkers of metabolic activity and stress (8‐hydroxydeoxyguanosine, cortisol, and testosterone). Results Fat‐free mass was the single strongest predictor of TEE among Hadza adults ( r 2 = 0.66, P < 0.001). Hadza men used greater daily walking distances and faster walking speeds compared with that of Hadza women, but neither sex nor any measure of physical activity or work load were correlated with TEE in analyses controlling for fat‐free mass. Compared with developed, industrial populations, Hadza adults had similar TEE but elevated levels of metabolic stress as measured by 8‐hydroxydeoxyguanosine. Conclusion Our results indicate that daily physical activity may not predict TEE within traditional hunter‐gatherer populations like the Hadza. Instead, adults with high levels of habitual physical activity may adapt by reducing energy allocation to other physiological activity. Am. J. Hum. Biol. 27:628–637, 2015. © 2015 Wiley Periodicals, Inc.