Association of supermarket characteristics with the body mass index of their shoppers.
BACKGROUND
Research on the built food environment and weight status has mostly focused on the presence/absence of food outlets while ignoring their internal features or where residents actually shop. We explored associations of distance travelled to supermarkets and supermarket characteristics with shoppers' body mass index (BMI).


METHODS
Shoppers (n=555) of five supermarkets situated in different income areas in the city were surveyed for food shopping habits, demographics, home postal code, height and weight. Associations of minimum distance to a supermarket (along road network, objectively measured using ArcGIS), its size, food variety and food basket price with shoppers' BMI were investigated. The 'food basket' was defined as the mixture of several food items commonly consumed by residents and available in all supermarkets.


RESULTS
Supermarkets ranged in total floor space (7500-135,000 square feet) and had similar varieties of fruits, vegetables and cereals. The majority of participants shopped at the surveyed supermarket more than once per week (mean range 1.2 ± 0.8 to 2.3 ± 2.1 times per week across the five supermarkets, p < 0.001), and identified it as their primary store for food (52% overall). Mean participant BMI of the five supermarkets ranged from 23.7 ± 4.3 kg/m² to 27.1 ± 4.3 kg/m² (p < 0.001). Median minimum distance from the shoppers' residence to the supermarket they shopped at ranged from 0.96 (0.57, 2.31) km to 4.30 (2.83, 5.75) km (p < 0.001). A negative association was found between food basket price and BMI. There were no associations between BMI and minimum distance to the supermarket, or other supermarket characteristics. After adjusting for age, sex, dissemination area median individual income and car ownership, BMI of individuals who shopped at Store 1 and Store 2, the supermarkets with lowest price of the 'food basket', was 3.66 kg/m² and 3.73 kg/m² higher compared to their counterparts who shopped at the supermarket where the 'food basket' price was highest (p < 0.001).


CONCLUSIONS
The food basket price in supermarkets was inversely associated with BMI of their shoppers. Our results suggest that careful manipulation of food prices may be used as an intervention for decreasing BMI.
Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6 British Columbia, Canada.
Scott A
SA
Lear
Danijela
D
Gasevic
Nadine
N
Schuurman
D000328:Adult; D000368:Aged; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D003132:Commerce; D003430:Cross-Sectional Studies; D003710:Demography; D005247:Feeding Behavior; D005260:Female; D005523:Food Supply / Q000191:economics*; D005638:Fruit / Q000191:economics; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D012111:Residence Characteristics; D057566:Self Report; D012959:Socioeconomic Factors; D014675:Vegetables / Q000191:economics