Consequences and Context of Stunting in the Amazon

University Of Georgia Research Foundation Inc, Athens GA

Investigators

Abstract

Research in anthropology has provided important insights into the adaptive nature of human growth, but more research is needed on how human growth may be shaped by changing local conditions and cultural factors, in order to understand the impact of early life factors on biological outcomes later in life. If conditions during early childhood growth are connected to later-life outcomes, then there should be a relationship between linear growth stunting early in life (2-5 years of age) and adult body proportions and fatness, as well as later measures of cardiovascular function (blood pressure) and metabolic rates. Additionally, this relationship should be particularly visible among groups who are experiencing lifestyle and nutrition transitions, or concurrent changes in diet and activity levels. To test these predictions, this project will collect data on diet, activity levels, household conditions (demographic information, wealth), and measures of body composition (height, weight, body fat), resting metabolic rate (a measure of energy use), and blood pressure in youth and adults from the Tsimane' population, an Amazonian society of farmers and foragers currently experiencing nutritional and socioeconomic change. Data from this project, combined with earlier waves of data collection on this population, will be used for growth curve modeling and statistical analysis to evaluate patterns of growth during rapid social and cultural change. Further, the results may be incorporated into disciplines such as developmental biology, pediatrics, as well as global and indigenous health, and therefore may provide insights into global nutrition transitions or contribute to understanding metabolic disorders in the U.S. and globally. The proposed research will contribute to student training, international collaborations, and science outreach in the research community. Human growth is fundamentally a biocultural process that is best understood through a life-history perspective. Life history theory explicitly grapples with how trade-offs between competing domains, such as growth, reproduction, and maintenance serve to enhance survival and reproduction in dynamic environments. Less research has focused explicitly on how growth patterns may be shaped by local conditions and, by extension, the relationship between early life growth trajectories and potential trade-offs that may result in downstream health outcomes. The investigators will collect, from across thirteen Tsimane' communities, demographic, economic, dietary, and nutritional information, as well as anthropometric measures of body composition (height, weight, skinfold measurements) for all participants, physical activity data and resting metabolic rate on a sub-sample of youth and adults, and blood pressure for all adults. Combining these data with a large, publically available longitudinal data set (Tsimane' Amazonian Panel Study) will allow statistical evaluation of hypotheses that build on the standard models of human growth, but incorporate measurements of changing socioeconomic and nutritional environments. Specifically, the hypotheses will evaluate: (1) the relationship between linear growth stunting early in life (2-5 years of age) and later body proportions and fatness, (2) the relationship between stunting and later measures of cardiovascular health (blood pressure) and metabolic rates, and (3) the relationship between household conditions, reliance on purchased foods, physical activity levels, and measures of body fatness.