Shelf Space: An Innovative Measure for Studying the Food Environment
Principal Investigator: Donald Rose, PhD
Department of Family Medicine and Community Health
Department of Community Health Sciences
Tulane University School of Public Health and Tropical Medicine
New Orleans, LA 70112
What's the problem?
The epidemic of overweight and obesity in the United States has prompted significant action on a number of fronts. Investigators, communities, and policymakers are working to understand the determinants and consequences of obesity and to develop interventions, programs, and policies that can help people achieve and maintain a healthy weight. A growing body of evidence indicates that Americans now live in an environment that predisposes them to overweight and obesity. Understanding this obesogenic environment is an important step in developing countervailing measures.
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How has this research addressed the problem?
For a number of years, Dr. Rose and his colleagues have been studying how neighborhood food availability influences consumer choice. Findings from his work and that of other researchers have shown relationships between the type of retail food outlets available in neighborhoods and weight status. For example, studies have shown positive associations between the presence of supermarkets and consumption of healthful foods and an inverse relationship between proximity to supermarkets and body mass index (BMI).
Dr. Rose and his research team have taken these studies a few steps further to develop a more nuanced understanding of neighborhood food environments, particularly those in low-income neighborhoods. He has examined not only the availability of stores in an area, but the nature of the foods offered in those stores. He also has expanded the definition of food outlets to include stores that are not traditionally associated with selling food items, such as liquor stores and drug stores.
In one particularly innovative advance, Dr. Rose and his team have used a new measure to examine food environments. Commercial marketers have long recognized that the amount of shelf space devoted to a product and its placement in a store, influence purchasing behavior. Dr. Rose explored this reality in two recent studies. One mapped retail food outlets, determined the shelf space devoted to fruits and vegetables compared with energy-dense snack foods, and conducted telephone interviews with residents of 103 randomly sampled urban census tracts in southeastern Louisiana. The second study measured the length of shelf space used for fruits, vegetables, and snack foods in 419 stores in 217 urban census tracts in southern Louisiana and Los Angeles County.
The first study found that the most frequently observed stores that sold food items were gas, convenience, and drug stores, followed by small food stores. One-quarter of the households had a supermarket within 1 kilometer of their residences, whereas three-quarters had a gas, convenience, or drugstore within the same distance. On average, households had 18 meters of fruit shelf-space, 34 meters of vegetable shelf-space, and 72 meters of candy shelf-space within 1 kilometer of their residences. The neighborhood availability of energy-dense snacks was modestly but significantly related to BMI, and an additional 100 meters of shelf-space for snack foods was associated with an increase in 0.1 BMI units.
The second study found that although supermarkets offered far more shelf space to fruits and vegetables than did other store types (medium and small food stores, convenience stores, drug stores, and liquor stores), they also devoted more shelf space to energy-dense snack foods than to fruits and vegetables. After supermarkets, drug stores had the most shelf space devoted to snack items. All of the stores devoted more shelf space to a limited number of snack items than to all fruits and vegetables.
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Significance of the research & results
Dr. Rose’s research has shown that it is not enough to characterize a food environment by store type. Understanding the foods available in those stores and recognizing that food is available in a variety of store types, including those not traditionally associated with food, also is critical. Given the emphasis on energy-dense, low-nutrient snacks in non-traditional food outlets, excluding them from studies underestimates the availability of unhealthy foods in communities. Dr. Rose’s shelf-space measure, which permits a comparison of the relative availability of healthful to non-healthful food items in stores, provides a valuable new tool for researchers, community decisionmakers, and policymakers to use in initiatives to improve health through dietary change.
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Recent related publications of interest
Bodor JN, Ulmer VM, Dunaway LF, Farley TA, Rose D. The rationale behind small food store interventions in low-income urban neighborhoods: insights from New Orleans. Journal of Nutrition 2010;140(6):1185-1188. [View Abstract]
Bodor JN, Rice JC, Farley TA, Swalm CM, Rose D. Disparities in food access: does aggregate availability of key foods from other stores offset the relative lack of supermarkets in African-American neighborhoods? Preventive Medicine 2010;51(1):63-67. [View Abstract]
Rose D, Bodor JN, Hutchinson PL, Swalm CM. The importance of a multi-dimensional approach for studying the links between food access and consumption. Journal of Nutrition 2010;140(6):1170-1174. [View Abstract]
Bodor JN, Rice JC, Farley TA, Swalm CM, Rose D. The association between obesity and urban food environments. Journal of Urban Health 2010;87(5):771-781. [View Abstract]
Farley TA, Rice J, Bodor JN, Cohen DA, Bluthenthal RN, Rose D. Measuring the food environment: Shelf space of fruits, vegetables, and snack foods in stores. Journal of Urban Health 2009;86(5):672-682. [View Abstract]
Rose D, Hutchinson PL, Bodor JN, Swalm CM, Farley TA, Cohen DA, Rice JC. Neighborhood food environments and body mass index: the importance of in-store contents. American Journal of Preventive Medicine 2009;37(3):214-219. [View Abstract]
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