title: Approximate Time to Steady-state Resting Energy Expenditure Using Indirect Calorimetry in Young, Healthy Adults.
abstract: Indirect calorimetry (IC) measurements to estimate resting energy expenditure (REE) necessitate a stable measurement period or steady state (SS). There is limited evidence when assessing the time to reach SS in young, healthy adults. The aims of this prospective study are to determine the approximate time to necessary reach SS using open-circuit IC and to establish the appropriate duration of SS needed to estimate REE. One hundred young, healthy participants (54 males and 46 females; age = 20.6 ± 2.1 years; body weight = 73.6 ± 16.3 kg; height 172.5 ± 9.3 cm; BMI = 24.5 ± 3.8 kg/m2) completed IC measurement for approximately 30 min while the volume of oxygen (VO2) and volume of carbon dioxide (VCO2) were collected. SS was defined by variations in the VO2and VCO2of ≤10% coefficient of variation (%CV) over a period of five consecutive minutes. The 30-min IC measurement was divided into six 5-min segments, such as S1, S2, S3, S4, S5, and S6. The results show that SS was achieved during S2 (%CV = 6.81 ± 3.2%), and the %CV continued to met the SS criteria for the duration of the IC measurement (S3 = 8.07 ± 4.4%, S4 = 7.93 ± 3.7%, S5 = 7.75 ± 4.1%, and S6 = 8.60 ± 4.6%). The current study found that in a population of young, healthy adults the duration of the IC measurement period could be a minimum of 10 min. The first 5-min segment was discarded, while SS occurred by the second 5-min segment.
authors.affiliation: Metabolic Laboratory, Department of Food, Nutrition and Packaging Sciences, College of Agriculture, Forestry and Life Sciences, Clemson University , Clemson, SC , USA.
authors.forename: Collin J
authors.initials: CJ
authors.lastname: Popp
authors.affiliation: Department of Biological Sciences, College of Agriculture, Forestry and Life Sciences, Clemson University , Clemson, SC , USA.
authors.forename: Jocelyn J
authors.initials: JJ
authors.lastname: Tisch
authors.affiliation: Department of Biological Sciences, College of Agriculture, Forestry and Life Sciences, Clemson University , Clemson, SC , USA.
authors.forename: Kenan E
authors.initials: KE
authors.lastname: Sakarcan
authors.affiliation: Department of Mathematical Sciences, College of Engineering and Science, Clemson University , Clemson, SC , USA.
authors.forename: William C
authors.initials: WC
authors.lastname: Bridges
authors.affiliation: Metabolic Laboratory, Department of Food, Nutrition and Packaging Sciences, College of Agriculture, Forestry and Life Sciences, Clemson University , Clemson, SC , USA.
authors.forename: Elliot D
authors.initials: ED
authors.lastname: Jesch
keywords: indirect calorimetry; methodology; resting energy expenditure; steady state