title: Markers of adiposity among children and adolescents: implications of the isotemporal substitution paradigm with sedentary behavior and physical activity patterns.
abstract: BACKGROUND
  The purpose of this study was to examine the association between daily movement patterns and dual energy X-ray absorptiometry-determined body fat percent (DXA-BF%) among children and adolescents while applying both traditional and novel analytical procedures.
  
  
  METHODS
  Using data from the cross-sectional 2003-2006 National Health and Nutrition Examination Survey (n = 5607), physical activity was assessed via accelerometry, with the following movement patterns assessed: 1) meeting moderate-to-vigorous physical activity (MVPA) guidelines and engaging in more light-intensity physical activity (LIPA) than sedentary behavior (SB); 2) meeting MVPA guidelines, but engaging in less LIPA than SB; 3) not meeting MVPA guidelines, but engaging in more LIPA than SB; and 4) not meeting MVPA guidelines and engaging in less LIPA than SB. Various markers of adiposity (e.g., DXA-BF%) were assessed.
  
  
  RESULTS
  Children in movement pattern 1 (52 %), compared to those in movement pattern 4, had significantly lower levels of BMI (∆ 2.2 kg/m(2)), waist circumference (∆ 6.5 cm), tricep skinfold (∆ 4.2 mm), subscapularis skinfold (∆ 2.6 mm), android BF% (∆ 7.6 %), gynoid BF% (∆ 5.1 %), and total BF% (∆ 5.2 %). Substituting 60 min/day of SB with MVPA resulted in a 4.6 % decreased estimate of total DXA-BF%. No findings were significant for adolescents.
  
  
  CONCLUSIONS
  The low proportion of children engaging in ≥ 60 min/day of MVPA and accumulating relatively more LIPA than SB had the lowest DXA-BF%.
authors.affiliation: Department of Health, Exercise Science, and Recreation Management, Center for Health Behavior Research, School of Applied Sciences, The University of Mississippi, 215 Turner Center, University, MS USA.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Loprinzi
authors.affiliation: Program in Exercise and Sport Science, School of Biological and Population Health Sciences, College of Public Health and Human Sciences, Oregon State University, Corvallis, OR USA.
authors.forename: Bradley J
authors.initials: BJ
authors.lastname: Cardinal
authors.affiliation: Department of Sport and Health Sciences, Sangmyung University, Seoul, South Korea.
authors.forename: Hyo
authors.initials: H
authors.lastname: Lee
authors.affiliation: Walking Behavior Laboratory, Population and Public Health Sciences, Pennington Biomedical Research Center, Baton Rouge, LA USA.
authors.forename: Catrine
authors.initials: C
authors.lastname: Tudor-Locke
keywords: Accelerometry; Epidemiology; Isotemporal substitution models; NHANES; Partition models