Measurement of Energy Expenditure by Indirect Calorimetry with a Whole-Room Calorimeter

Energy plays a vital role in biological processes. To assess energy metabolism status in a large population cohort, the standard operating procedure for measuring energy expenditure measurement using a whole-room calorimeter was purposed in this study. This protocol illustrates the procedure and specific details for validating methanol burning and evaluating the metabolic status of volunteers. In metabolic status evaluation, the (1) O₂ consumption, (2) CO₂ production, (3) energy expenditure, and (4) respiratory exchange ratio were first measured at resting and provided as basic phenotype items in Human Phenotype Atlas. Besides, it includes the procedure and results for measuring exercise-related activity thermogenesis and evaluating the impact of environmental temperature on energy metabolism. These results demonstrate the broader utility of the whole-room calorimeter. The implementation of this protocol is expected to enhance the data comparability in Human Phenotype Atla and provide a valuable reference for metabolism-related studies.