Validity and reproducibility of a novel method for time‐course evaluation of diet‐induced thermogenesis in a respiratory chamber

• Published in: Physiological reports Vol. 3; no. 5; pp. e12410 - n/a
• Main Authors: Usui, Chiyoko, Ando, Takafumi, Ohkawara, Kazunori, Miyake, Rieko, Oshima, Yoshitake, Hibi, Masanobu, Oishi, Sachiko, Tokuyama, Kumpei, Tanaka, Shigeho
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01.05.2015; BlackWell Publishing Ltd
• Subjects: Accelerometers; Diet; Diet‐induced thermogenesis; Energy; Energy expenditure; Fasting; Households; Metabolic rate; Nutrition research; Original Research; Physical activity; Physiology; Radar systems; Reproducibility; Respiration; respiratory chamber; Sleep and wakefulness; Studies; Thermogenesis; triaxial accelerometry; Validity; Diet‐induced thermogenesis; triaxial accelerometry; respiratory chamber; validity; reproducibility
• ISSN: 2051-817X; 2051-817X
• DOI: 10.14814/phy2.12410

We developed a novel method for computing diet‐induced thermogenesis (DIT) in a respiratory chamber and evaluated the validity and reproducibility of the method. We hypothesized that DIT may be calculated as the difference between postprandial energy expenditure (EE) and estimated EE (sum of basal metabolic rate and physical activity (PA)‐related EE). The estimated EE was derived from the regression equation between EE from respiration and PA intensity in the fasting state. It may be possible to evaluate the time course of DIT using this novel technique. In a validity study, we examined whether DIT became zero (theoretical value) for 6 h of fasting in 11 subjects. The mean value of DIT calculated by the novel and traditional methods was 22.4 ± 13.4 and 3.4 ± 31.8 kcal/6 h, respectively. In the reproducibility study, 15 adult subjects lived in the respiratory chamber for over 24 h on two occasions. The DIT over 15 h of postprandial wake time was calculated. There were no significant differences in the mean values of DIT between the two test days. The within‐subject day‐to‐day coefficient of variation for calculated DIT with the novel and traditional methods was approximately 35% and 25%, respectively. The novel method did not have superior reproducibility compared with that of the traditional method. However when comparing the smaller variation in the fasting state than the theoretical value (zero), the novel method may be better for evaluating interindividual differences in DIT than the traditional method and also has the ability to evaluate the time‐course. In order to improve the traditional method for computing diet‐induced thermogenesis (DIT) in a respiratory chamber, we developed a novel method and evaluated the validity and reproducibility of the method. We report that the novel method did not have superior reproducibility compared with that of the traditional method. However, our results suggested that the novel method may be better for evaluating inter‐individual differences in DIT than the traditional method and also has the ability to evaluate the time‐course of DIT.