title: A novel approach to calculating the thermic effect of food in a metabolic chamber.
abstract: The thermic effect of food (TEF) is the well-known concept in spite of its difficulty for measuring. The gold standard for evaluating the TEF is the difference in energy expenditure between fed and fasting states (ΔEE). Alternatively, energy expenditure at 0 activity (EE0) is estimated from the intercept of the linear relationship between energy expenditure and physical activity to eliminate activity thermogenesis from the measurement, and the TEF is calculated as the difference between EE0 and postabsorptive resting metabolic rate (RMR) or sleeping metabolic rate (SMR). However, the accuracy of the alternative methods has been questioned. To improve TEF estimation, we propose a novel method as our original TEF calculation method to calculate EE0 using integrated physical activity over a specific time interval. We aimed to identify which alternative methods of TEF calculation returns reasonable estimates, that is, positive value as well as estimates close to ΔEE. Seven men participated in two sessions (with and without breakfast) of whole-body indirect calorimetry, and physical activity was monitored with a triaxial accelerometer. Estimates of TEF by three simplified methods were compared to ΔEE. ΔEE, EE0 above SMR, and our original method returned positive values for the TEF after breakfast in all measurements. TEF estimates of our original method was indistinguishable from those based on the ΔEE, whereas those as EE0 above RMR and EE0 above SMR were slightly lower and higher, respectively. Our original method was the best among the three simplified TEF methods as it provided positive estimates in all the measurements that were close to the value derived from gold standard for all measurements.
authors.affiliation: Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan Research Fellow of the Japan Society for the Promotion of Science, Tokyo, Japan.
authors.forename: Hitomi
authors.initials: H
authors.lastname: Ogata
authors.affiliation: Graduate School of Comprehensive Human Science, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Fumi
authors.initials: F
authors.lastname: Kobayashi
authors.affiliation: Health Care Food Research Laboratories, Kao Corporation, Tokyo, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Hibi
authors.affiliation: Department of Nutritional Science, National Institute of Health and Nutrition, Tokyo, Japan.
authors.forename: Shigeho
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan tokuyama@taiiku.tsukuba.ac.jp.
authors.forename: Kumpei
authors.initials: K
authors.lastname: Tokuyama
mesh_terms: D061725:Accelerometry / Q000379:methods*; D002153:Calorimetry, Indirect / Q000379:methods*; D004734:Energy Metabolism / Q000502:physiology*; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D055815:Young Adult
keywords: Integrated physical activity; nonexercise activity thermogenesis; thermic effect of food; whole‐body indirect calorimetry