title: Objective vs. Self-report Sedentary Behavior in Overweight and Obese Young Adults.
abstract: BACKGROUND
  Sedentary behavior (SED) has been measured almost exclusively by self-reported total SED or television time in longitudinal studies. This manuscript aimed to compare self-reported vs. objectively measured SED.
  
  
  METHODS
  Among overweight and obese young adults enrolled in a weight loss trial, baseline SED was assessed by 3 methods: 1) a questionnaire assessing 8 common SEDs (SEDQ), 2) 1 question assessing SED from the Global Physical Activity Questionnaire (SEDGPAQ), and 3) a monitor worn on the arm (SEDOBJ). In addition, television time (SEDTV) was isolated from the SEDQ. SED measures were compared using Spearman's correlations, signed-rank tests, and Bland-Altman plots.
  
  
  RESULTS
  In 448 participants, SEDQ and SEDGPAQ were only weakly associated with SEDOBJ (rs = 0.21; P < .001, rs = 0.32; P < .001, respectively). Compared with SEDOBJ, SEDQ more often overestimated SEDOBJ (median difference: 1.1 hours/day; P < .001), while SEDGPAQ more often underestimated SEDOBJ (median difference: -0.7 hours/day; P < .001). The correlation between SEDTV and SEDOBJ was not significantly different from 0 (rs = 0.08; P = .08).
  
  
  CONCLUSIONS
  SEDQ and SEDGPAQ were weakly correlated with, and significantly different from, SEDOBJ in overweight and obese young adults. SEDTV was not related to SEDOBJ. The poor associations of self-reported and objectively measured SED could affect interpretation and comparison across studies relating SED to adverse health outcomes.
authors.affiliation: Dept of Health and Physical Activity, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Bethany
authors.initials: B
authors.lastname: Barone Gibbs
authors.forename: Wendy C
authors.initials: WC
authors.lastname: King
authors.forename: Kelliann K
authors.initials: KK
authors.lastname: Davis
authors.forename: Amy D
authors.initials: AD
authors.lastname: Rickman
authors.forename: Renee J
authors.initials: RJ
authors.lastname: Rogers
authors.forename: Abdus
authors.initials: A
authors.lastname: Wahed
authors.forename: Steven H
authors.initials: SH
authors.lastname: Belle
authors.forename: John
authors.initials: J
authors.lastname: Jakicic
mesh_terms: D056044:Actigraphy / Q000379:methods*; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000523:psychology*; D010809:Physical Fitness / Q000502:physiology*; D057185:Sedentary Behavior; D057566:Self Report; D011795:Surveys and Questionnaires; D013690:Television; D055815:Young Adult