title: Development of an accelerometer-based multivariate model to predict free-living energy expenditure in a large military cohort.
abstract: This study developed a multivariate model to predict free-living energy expenditure (EE) in independent military cohorts. Two hundred and eighty-eight individuals (20.6 ± 3.9 years, 67.9 ± 12.0 kg, 1.71 ± 0.10 m) from 10 cohorts wore accelerometers during observation periods of 7 or 10 days. Accelerometer counts (PAC) were recorded at 1-minute epochs. Total energy expenditure (TEE) and physical activity energy expenditure (PAEE) were derived using the doubly labelled water technique. Data were reduced to n = 155 based on wear-time. Associations between PAC and EE were assessed using allometric modelling. Models were derived using multiple log-linear regression analysis and gender differences assessed using analysis of covariance. In all models PAC, height and body mass were related to TEE (P < 0.01). For models predicting TEE (r (2) = 0.65, SE = 462 kcal · d(-1) (13.0%)), PAC explained 4% of the variance. For models predicting PAEE (r (2) = 0.41, SE = 490 kcal · d(-1) (32.0%)), PAC accounted for 6% of the variance. Accelerometry increases the accuracy of EE estimation in military populations. However, the unique nature of military life means accurate prediction of individual free-living EE is highly dependent on anthropometric measurements.
authors.affiliation: University of Bath, Department for Health, Bath, United Kingdom.
authors.forename: Fleur
authors.initials: F
authors.lastname: Horner
authors.forename: James L
authors.initials: JL
authors.lastname: Bilzon
authors.forename: Mark
authors.initials: M
authors.lastname: Rayson
authors.forename: Sam
authors.initials: S
authors.lastname: Blacker
authors.forename: Victoria
authors.initials: V
authors.lastname: Richmond
authors.forename: James
authors.initials: J
authors.lastname: Carter
authors.forename: Anthony
authors.initials: A
authors.lastname: Wright
authors.forename: Alan
authors.initials: A
authors.lastname: Nevill
mesh_terms: D056044:Actigraphy / Q000379:methods*; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001827:Body Height; D001835:Body Weight; D015331:Cohort Studies; D004734:Energy Metabolism; D015444:Exercise; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008889:Military Personnel; D008954:Models, Biological; D009043:Motor Activity; D015203:Reproducibility of Results; D012737:Sex Factors; D055815:Young Adult