Annals of human biology

1464-50335112024FebAnnals of human biologyAnn Hum BiolTotal daily energy expenditure and elevated water turnover in a small-scale semi-nomadic pastoralist society from Northern Kenya.2310724231072410.1080/03014460.2024.2310724Pastoralists live in challenging environments, which may be accompanied by unique activity, energy, and water requirements.Few studies have examined whether the demands of pastoralism contribute to differences in total energy expenditure (TEE) and water turnover (WT) compared to other lifestyles.Accelerometer-derived physical activity, doubly labelled water-derived TEE and WT, and anthropometric data were collected for 34 semi-nomadic Daasanach adults from three northern Kenyan communities with different levels of pastoralist activity. Daasanach TEEs and WTs were compared to those of other small-scale and industrialised populations.When modelled as a function of fat-free-mass, fat-mass, age, and sex, TEE did not differ between Daasanach communities. Daasanach TEE (1564-4172 kcal/day) was not significantly correlated with activity and 91% of TEEs were within the range expected for individuals from comparison populations. Mean WT did not differ between Daasanach communities; Daasanach absolute (7.54 litres/day men; 7.46 litres/day women), mass-adjusted, and TEE-adjusted WT was higher than most populations worldwide.The similar mass-adjusted TEE of Daasanach and industrialised populations supports the hypothesis that habitual TEE is constrained, with physically demanding lifestyles necessitating trade-offs in energy allocation. Elevated WT in the absence of elevated TEE likely reflects a demanding active lifestyle in a hot, arid climate.McGroskyAmandaAEvolutionary Anthropology, Duke University, Durham, NC, USA.SwansonZane SZSEvolutionary Anthropology, Duke University, Durham, NC, USA.Global Food and Water Security Program, Center for Strategic and International Studies, Washington, WA, USA.RimbachRebeccaREvolutionary Anthropology, Duke University, Durham, NC, USA.Department of Behavioural Biology, University of Münster, Münster, Germany.BethancourtHilaryHDepartment of Anthropology, Northwestern University, Evanston, IL, USA.NdiemaEmmanuelEDepartment of Earth Sciences, National Museums of Kenya, Nairobi, Kenya.NzunzaRosemaryRKenya Medical Research Institute, Nairobi, Kenya.BraunDavid RDRCenter for the Advanced Study of Human Paleobiology, Anthropology Department, George Washington University, Washington, WA, USA.Technological Primate Research Group, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.RosingerAsher YAYDepartment of Biobehavioral Health, PA State University, University Park, PA, USA.Department of Anthropology, Pennsylvania State University, State College, PA, USA.PontzerHermanHEvolutionary Anthropology, Duke University, Durham, NC, USA.Duke Global Health Institute, Duke University, Durham, NC, USA.engP30 AG034424AGNIA NIH HHSUnited StatesJournal Article20240304