title: Neighbourhood built environment associations with body size in adults: mediating effects of activity and sedentariness in a cross-sectional study of New Zealand adults.
abstract: BACKGROUND
  The aim of this study was to determine the associations between body size and built environment walkability variables, as well as the mediating role of physical activity and sedentary behaviours with body size.
  
  
  METHODS
  Objective environment, body size (body mass index (BMI), waist circumference (WC)), and sedentary time and physical activity data were collected from a random selection of 2033 adults aged 20-65 years living in 48 neighbourhoods across four New Zealand cities. Multilevel regression models were calculated for each comparison between body size outcome and built environment exposure.
  
  
  CONCLUSIONS
  Street connectivity and neighborhood destination accessibility were significant predictors of body size (1 SDchange predicted a 1.27 to 1.41 % reduction in BMI and a 1.76 to 2.29 % reduction in WC). Significantrelationships were also observed for streetscape (1 SD change predicted a 1.33 % reduction in BMI) anddwelling density (1 SD change predicted a 1.97 % reduction in BMI). Mediation analyses revealed asignificant mediating effect of physical activity on the relationships between body size and street connectivity and neighbourhood destination accessibility (explaining between 10.4 and 14.6 % of the total effect). No significant mediating effect of sedentary behaviour was found. Findings from this cross-sectional study of a random selection of New Zealand adults are consistent with international research. Findings are limited to individual environment features only; conclusions cannot be drawn about the cumulative and combined effect of individual features on outcomes.
  
  
  CONCLUSIONS
  Built environment features were associated with body size in the expected directions. Objectively-assessed physical activity mediated observed built environment-body size relationships.
authors.affiliation: Human Potential Centre, Auckland University of Technology, Auckland, New Zealand. melody.oliver@aut.ac.nz.
authors.forename: Melody
authors.initials: M
authors.lastname: Oliver
authors.affiliation: SHORE and Whāriki Research Centre, Massey University, Auckland, New Zealand. k.witten@massey.ac.nz.
authors.forename: Karen
authors.initials: K
authors.lastname: Witten
authors.affiliation: Department of Public Health, University of Otago, Wellington, New Zealand. tony.blakely@otago.ac.nz.
authors.forename: Tony
authors.initials: T
authors.lastname: Blakely
authors.affiliation: SHORE and Whāriki Research Centre, Massey University, Auckland, New Zealand. k.parker1@massey.ac.nz.
authors.forename: Karl
authors.initials: K
authors.lastname: Parker
authors.affiliation: McCaughey VicHealth Community Wellbeing Unit, The University of Melbourne, Melbourne, Australia. hannah.badland@unimelb.edu.au.
authors.forename: Hannah
authors.initials: H
authors.lastname: Badland
authors.affiliation: Human Potential Centre, Auckland University of Technology, Auckland, New Zealand. grant.schofield@aut.ac.nz.
authors.forename: Grant
authors.initials: G
authors.lastname: Schofield
authors.affiliation: Department of Public Health, University of Otago, Wellington, New Zealand. vivienne.ivory@otago.ac.nz.
authors.forename: Vivienne
authors.initials: V
authors.lastname: Ivory
authors.affiliation: School of GeoSciences, University of Edinburgh, Edinburgh, Scotland, UK. jamie.pearce@ed.ac.uk.
authors.forename: Jamie
authors.initials: J
authors.lastname: Pearce
authors.affiliation: SHORE and Whāriki Research Centre, Massey University, Auckland, New Zealand. suzanne.mavoa@unimelb.edu.au.|McCaughey VicHealth Community Wellbeing Unit, The University of Melbourne, Melbourne, Australia. suzanne.mavoa@unimelb.edu.au.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Mavoa
authors.affiliation: Human Potential Centre, Auckland University of Technology, Auckland, New Zealand. erica.hinckson@aut.ac.nz.
authors.forename: Erica
authors.initials: E
authors.lastname: Hinckson
authors.affiliation: SHORE and Whāriki Research Centre, Massey University, Auckland, New Zealand. p.sweetsur@massey.ac.nz.
authors.forename: Paul
authors.initials: P
authors.lastname: Sweetsur
authors.affiliation: School of Environment, The University of Auckland, Auckland, New Zealand. r.kearns@auckland.ac.nz.
authors.forename: Robin
authors.initials: R
authors.lastname: Kearns
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D049628:Body Size; D002947:Cities; D003430:Cross-Sectional Studies; D004779:Environment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D009765:Obesity / Q000453:epidemiology / Q000517:prevention & control*; D012111:Residence Characteristics; D057185:Sedentary Behavior; D055815:Young Adult