Identifying supermarket characteristics that may influence diet

Objective: We conducted an audit of 62 supermarkets in six NC counties to assess food cost, quality and variety, and external and internal store characteristics to understand how supermarkets may differ in health promoting cues. Methods: We used the USDA Thrifty Food Plan bread basket survey to differentiate the cost to feed a family of four for two weeks. Examples of external observations were number and type of restaurants and vending, and internal observations were variety of fresh produce, health promotion signs, and identification of WIC items. Supermarkets were grouped into five categories: chain 1, chain 2, other, superstores, and health food. T-test and χ2 were used to assess significant differences by store type. Results: The average cost of the TFP was $259.31, ranging from $202.50 in superstores to $384.99 in health food stores. On average, chain 1 had almost six fast food restaurants share its parking lot compared to less than 2 for other supermarket and none at health food stores. Chain 1 had vending machines at all locations, compared to 25% to 75% of other supermarkets, and none at health food stores. Chain 1 had the least produce variety, and the smallest produce/store ratio, than all other stores. All supermarkets except superstores had health promotion signs. WIC items were displayed in all chain 1 stores, in most other supermarkets; however, WIC was not accepted at health food stores. Conclusion: Food cost, variety, store characteristics and health promoting cues varied among the 62 stores and may influence food purchases.