Accelerometer thresholds: Accounting for body mass reduces discrepancies between measures of physical activity for individuals with overweight and obesity

• Published in: Applied physiology, nutrition, and metabolism Vol. 42; no. 1; p. 53
• Main Authors: Raiber, Lilian, Christensen, Rebecca A G, Jamnik, Veronica K, Kuk, Jennifer L
• Format: Journal Article
• Language: English
• Published: Canada 01-01-2017
• Subjects: Actigraphy; Adult; Algorithms; Basal Metabolism; Body Mass Index; Body Weight; Energy Metabolism; Exercise; Female; Guidelines as Topic; Health Promotion; Healthy Lifestyle; Humans; Male; Models, Biological; Nutrition Surveys; Obesity - metabolism; Obesity - therapy; Overweight - metabolism; Overweight - therapy; Physical Exertion; Reproducibility of Results; Self Report; United States; accelerometry; indice de masse corporelle; activité physique; body mass index; intensity thresholds; seuils d’intensité; accélérométrie; physical activity
• ISSN: 1715-5320
• DOI: 10.1139/apnm-2016-0303

The objective of this study was to explore whether accelerometer thresholds that are adjusted to account for differences in body mass influence discrepancies between self-report and accelerometer-measured physical activity (PA) volume for individuals with overweight and obesity. We analyzed 6164 adults from the National Health and Nutrition Examination Survey between 2003-2006. Established accelerometer thresholds were adjusted to account for differences in body mass to produce a similar energy expenditure (EE) rate as individuals with normal weight. Moderate-, vigorous-, and moderate- to vigorous-intensity PA (MVPA) durations were measured using established and adjusted accelerometer thresholds and compared with self-report. Durations of self-report were longer than accelerometer-measured MVPA using established thresholds (normal weight: 57.8 ± 2.4 vs 9.0 ± 0.5 min/day, overweight: 56.1 ± 2.7 vs 7.4 ± 0.5 min/day, and obesity: 46.5 ± 2.2 vs 3.7 ± 0.3 min/day). Durations of subjective and objective PA were negatively associated with body mass index (BMI) (P < 0.05). Using adjusted thresholds increased MVPA durations, and reduced discrepancies between accelerometer and self-report measures for overweight and obese groups by 6.0 ± 0.3 min/day and 17.7 ± 0.8 min/day, respectively (P < 0.05). Using accelerometer thresholds that represent equal EE rates across BMI categories reduced the discrepancies between durations of subjective and objective PA for overweight and obese groups. However, accelerometer-measured PA generally remained shorter than durations of self-report within all BMI categories. Further research may be necessary to improve analytical approaches when using objective measures of PA for individuals with overweight or obesity.