title: The correlation between supermarket size and national obesity prevalence.
abstract: BACKGROUND
  Supermarkets provide healthy and affordable food options while simultaneously heavily promoting energy-dense, nutrient-poor foods and drinks. Store size may impact body weight via multiple mechanisms. Large stores encourage purchasing of more food in a single visit, and in larger packages. In addition they provide greater product choice (usually at lower prices) and allow greater exposure to foods of all types. These characteristics may promote purchasing and consumption. Our objective was to assess the relationship between supermarket size and obesity, which has rarely been assessed.
  
  
  RESULTS
  Data on supermarket size (measured as total aisle length in metres) was from 170 stores in eight developed countries with Western-style diets. Data for national obesity prevalence was obtained from the UK National Obesity Observatory. We found a strong correlation between average store size and national obesity prevalence (r = 0.96).
  
  
  CONCLUSIONS
  Explanations for the association between store size and national obesity prevalence may include larger and less frequent shopping trips and greater choice and exposure to foods in countries with larger stores. Large supermarkets may represent a food system that focuses on quantity ahead of quality and therefore may be an important and novel environmental indicator of a pattern of behaviour that encourages obesity.
authors.affiliation: World Health Organization (WHO) Collaborating Centre for Obesity Prevention, Deakin University, Melbourne Burwood Campus, 221 Burwood Highway, Burwood Victoria, 3125 Australia.
authors.forename: Adrian J
authors.initials: AJ
authors.lastname: Cameron
authors.affiliation: National Institute for Health Innovation, School of Population Health, The University of Auckland, Auckland, New Zealand.
authors.forename: Wilma E
authors.initials: WE
authors.lastname: Waterlander
authors.affiliation: Metropolitan University College, Copenhagen, Denmark.
authors.forename: Chalida M
authors.initials: CM
authors.lastname: Svastisalee
keywords: Food environment; Store size; Supermarket