HRRBAA: The metabolic cost of living among herders

受限总能量消耗假说表明，面对高水平的体力活动，人体努力减少每天燃烧的总卡路里数量。然而，人类生活在狭窄的新陈代谢范围内的想法还没有在气候和季节之间得到广泛测试。为了进一步解决这一假设，这项高风险研究项目将评估在高度活跃的寒冷气候人口中测量能量消耗和棕色脂肪组织激活的可行性。这一努力将产生的基础人类生物学研究将使我们了解新陈代谢和棕色脂肪组织如何与现代世界的肥胖症流行有关。这项研究将支持本科生和研究生的研究培训和指导、国际合作以及对当地社区的科学推广。结果将在同行评议期刊上传播，并纳入奥尔巴尼大学的本科生和研究生课程。使用弹性心率和双重标记水法，总能量消耗(每天燃烧的卡路里)将在牛群围捕期间测量，在晚秋持续大约一周。在此期间，还将记录体力活动水平(用于估计和比较能量消耗)和饮食摄入量。每个受试者的静息代谢率、年龄、性别、体重、体脂百分比、肌肉质量、血糖水平和胆固醇水平都将被记录下来。这些数据将被用来开发新陈代谢图谱，确定不同活动和休息期间消耗了多少卡路里。能量消耗测量将与估计进行比较，以确定牧民消耗的卡路里是否低于人类能量消耗的新约束理论所假设的那样，或者测量结果是否反映了居住在恶劣环境中所需的更高能量需求。最后，一种使用热像仪的新程序将被用来在野外测量棕色脂肪组织的激活。通常，棕色脂肪组织研究在临床环境中进行，需要进行PET-CT扫描；这项研究中使用的程序对研究人员和现场研究参与者来说都更灵活。这个项目将作为一个跳板，用于开发一项纵向研究，检查季节性对总能量消耗、体力活动水平、棕色脂肪组织激活的影响，以及应对肥胖流行病的应用。

The constrained total energy expenditure hypothesis suggests that in the face of high levels of physical activity the human body works to reduce the overall number of calories burned each day. However, the idea that humans live within a narrow metabolic range has not been broadly tested across climates and seasons. To further address this hypothesis, this high-risk research project will assess feasibility of measuring energy expenditure and brown adipose tissue activation in a highly active cold-climate population. The fundamental human biology research that would result from this effort will inform our understanding of how metabolism and brown adipose tissue relate to the obesity epidemic in the modern world. The research will support research training and mentoring for undergraduate and graduate students, international collaborations, and science outreach to local communities. Results will be disseminated in peer review journals as well as incorporated into undergraduate and graduate curricula at the University at Albany. Using the flex-heart rate and doubly labeled water methods, total energy expenditure (calories burned each day) will be measured during the herd round-up, which lasts roughly one week during the late fall. Physical activity levels (used to estimate and compare energy expenditures) and dietary intake will also be documented during this time. Resting metabolic rate, age, sex, body mass, body fat percentage, muscle mass, glucose levels, and cholesterol levels will be recorded for each subject. These data will be used to develop a metabolic profile, determining how many calories are used for different activities and during rest. Energy expenditure measurements will be compared to estimates to determine if herders expend fewer calories than expected, as hypothesized by the new constrained theory for human energy expenditure, or if the measurements reflect a higher energetic demand required by inhabiting a harsh environment. Finally, a new procedure employing a thermal imaging camera will be used to measure brown adipose tissue activation in the field. Typically, brown adipose tissue studies take place in clinical settings and require PET-CT scans; the procedure used in this study is more flexible for both researchers and study participants in the field. This project will act as a spring board for developing a longitudinal study examining seasonal impacts on total energy expenditure, physical activity levels, brown adipose tissue activation, and applications for addressing the obesity epidemic.