Proposed shorter duration protocols for measuring resting energy expenditure utilizing whole room indirect calorimetry.

Abstract Background Sixty-minutes is currently the shortest testing duration for 24-hour resting energy expenditure (24-h REE) utilizing whole room indirect calorimetry. Objective Show that recalculated 30-minute extrapolated 24-h REE from previously published 60-minute metabolic data are valid. Methods Propane consumption linearity was determined through an eight-hour combustion test. Thereafter, metabolic data for 24-h extrapolated ventilation rates of oxygen (VO₂; l/d), carbon dioxide (VCO₂; l/d), respiratory quotient (RQ; VCO₂/VO₂) and REE (MJ/d) from ten 60-minute propane combustion tests were recalculated to reflect a 30-minute testing duration. A similar analysis was performed utilizing data from 60-minute subject metabolic measurements within a whole room indirect calorimeter (4,597 liters) specific for measuring resting energy expenditure (REE). Statistical (p < 0.05) comparisons between recalculated and original 60-minute metabolic data were determined by SPSS (version 27). Results Propane consumption during a combustion test was found to be linear for up to eight-hours. Furthermore, no differences existed between propane stoichiometry and combustion for any of the extrapolated 24-h metabolic parameters when recalculated from 60-minute propane combustion data to reflect a 30-minute duration. Finally, similar results were obtained for all recalculated subject metabolic data. Conclusions Recalculated extrapolated 24-h metabolic data derived from a 30-minute testing duration appear to be valid. This suggests that whole room indirect calorimetry could be an adjunct for various weight loss or other programs where accurate metabolic measurements are required.