title: Influences of the neighbourhood food environment on adiposity of low-income preschool-aged children in Los Angeles County: a longitudinal study.
abstract: BACKGROUND
  Few studies have examined the association between the food environment and adiposity in early childhood, a critical time for obesity prevention. The objective of this study was to examine the longitudinal association between neighbourhood food environment and adiposity among low-income preschool-aged children in a major metropolitan region in the USA.
  
  
  METHODS
  The study sample was 32 172 low-income preschool-aged children in Los Angeles County who had repeated weight and height measurements collected between ages 2 and 5 years through a federal nutrition assistance programme. We conducted multilevel longitudinal analyses to examine how spatial densities of healthy and unhealthy retail food outlets in the children's neighbourhoods were related to adiposity, as measured by weight-for-height z-score (WHZ), while controlling for neighbourhood-level income and education, family income, maternal education, and child's gender and race/ethnicity.
  
  
  RESULTS
  Density of healthy food outlets was associated with mean WHZ at age 3 in a non-linear fashion, with mean WHZ being lowest for those exposed to approximately 0.7 healthy food outlets per square mile and higher for lesser and greater densities. Density of unhealthy food outlets was not associated with child WHZ.
  
  
  CONCLUSIONS
  We found a non-linear relationship between WHZ and density of healthy food outlets. Research aiming to understand the sociobehavioural mechanisms by which the retail food environment influences early childhood obesity development is complex and must consider contextual settings.
authors.affiliation: Centre for Health Equity Studies (CHESS), Stockholm University and Karolinska Institute, Stockholm, Sweden Department of Community Health Sciences, UCLA Fielding School of Public Health, Los Angeles, California, USA.
authors.forename: M Pia
authors.initials: MP
authors.lastname: Chaparro
authors.affiliation: Public Health Foundation Enterprises-Special Supplemental Nutrition Program for Women, Infants and Children (PHFE-WIC), Irwindale, California, USA.
authors.forename: Shannon E
authors.initials: SE
authors.lastname: Whaley
authors.affiliation: Department of Biostatistics, UCLA Fielding School of Public Health, University of California, Los Angeles, Los Angeles, California, USA.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Crespi
authors.affiliation: Department of Health Science, California State Fullerton, Fullerton, California, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Koleilat
authors.affiliation: Department of Community Health Sciences, UCLA Fielding School of Public Health, Los Angeles, California, USA.
authors.forename: Tabashir Z
authors.initials: TZ
authors.lastname: Nobari
authors.affiliation: Department of Environmental & Occupational Health Sciences, School of Public Health, University of Washington, Seattle, Washington, USA.
authors.forename: Edmund
authors.initials: E
authors.lastname: Seto
authors.affiliation: Department of Community Health Sciences, UCLA Fielding School of Public Health, Los Angeles, California, USA.
authors.forename: May C
authors.initials: MC
authors.lastname: Wang
mesh_terms: D000273:Adipose Tissue; D001741:Black or African American / Q000706:statistics & numerical data; D001213:Asian / Q000706:statistics & numerical data; D001827:Body Height; D001835:Body Weight; D002675:Child, Preschool; D005260:Female; D063105:Food Assistance / Q000706:statistics & numerical data; D005523:Food Supply / Q000191:economics / Q000706:statistics & numerical data*; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D008137:Longitudinal Studies; D015141:Los Angeles / Q000453:epidemiology; D008297:Male; D009035:Mothers / Q000193:education; D055361:Multilevel Analysis; D063766:Pediatric Obesity / Q000191:economics / Q000453:epidemiology / Q000209:etiology*; D011204:Poverty Areas; D012111:Residence Characteristics; D012307:Risk Factors; D017678:Sex Distribution
keywords: Environmental epidemiology; OBESITY; PUBLIC HEALTH