Consequences and Context of Stunting in the Amazon

人类学研究为人类成长的适应性本质提供了重要的见解，但为了了解早期生活因素对生命后期生物结果的影响，需要更多的研究来了解人类成长如何通过改变当地条件和文化因素来塑造。如果幼儿时期的生长状况与以后的生活结果有关，那么在生命早期（2-5岁）的线性生长发育迟缓与成年后的身体比例和肥胖，以及后来的心血管功能（血压）和代谢率之间应该存在关系。此外，在经历生活方式和营养转变，或饮食和活动水平同时发生变化的人群中，这种关系应该特别明显。为了验证这些预测，该项目将收集提斯曼人口中年轻人和成年人的饮食、活动水平、家庭条件（人口统计信息、财富）、身体成分（身高、体重、体脂）、静息代谢率（能量消耗的一种指标）和血压等数据。提斯曼是亚马逊地区的一个农民和采集者社会，目前正经历着营养和社会经济变化。从这个项目获得的数据，结合先前收集的关于这一人口的数据，将用于建立增长曲线模型和统计分析，以评估社会和文化迅速变化期间的增长模式。此外，研究结果可能被纳入诸如发育生物学、儿科学以及全球和土著健康等学科，因此可能为全球营养转变提供见解，或有助于理解美国和全球的代谢紊乱。拟议的研究将有助于学生培训，国际合作和科学推广在研究界。从根本上说，人类的成长是一个生物文化过程，最好通过生活史的角度来理解。生命史理论明确地阐述了如何在竞争领域之间进行权衡，如生长、繁殖和维持，以提高动态环境中的生存和繁殖。很少有研究明确关注当地条件如何影响生长模式，进而关注生命早期生长轨迹与可能导致下游健康结果的潜在权衡之间的关系。研究人员将从13个提斯曼社区收集人口统计、经济、饮食和营养信息，以及所有参与者的身体组成（身高、体重、皮褶测量）的人体测量数据，青年和成人亚样本的身体活动数据和静息代谢率，以及所有成年人的血压。将这些数据与一个大型的、公开的纵向数据集（Tsimane的亚马逊小组研究）结合起来，将允许对建立在人类生长标准模型上的假设进行统计评估，但纳入了不断变化的社会经济和营养环境的测量。具体来说，这些假设将评估：(1)生命早期（2-5岁）线性生长发育迟缓与后来的身体比例和肥胖之间的关系，(2)发育迟缓与后来的心血管健康（血压）和代谢率之间的关系，以及(3)家庭条件、对购买食物的依赖、身体活动水平和身体肥胖测量之间的关系。

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.