You can use the Food Environment Atlas, from the USDA Economic Research Service to create a map, selecting from criteria such as availability of food stores, availablility of restaurants, food security, food assistance, food prices and taxes and much more.
"Food Choices--Indicators of the community's access to and acquisition of healthy, affordable food, such as: access and proximity to a grocery store; number of foodstores and restaurants; expenditures on fast foods; food and nutrition assistance program participation; food prices; food taxes; and availability of local foods
Health and Well-Being--Indicators of the community's success in maintaining healthy diets, such as: food insecurity; diabetes and obesity rates; and physical activity levels
Community Characteristics--Indicators of community characteristics that might influence the food environment, such as: demographic composition; income and poverty; population loss; metro-nonmetro status; natural amenities; and recreation and fitness centers
The Atlas currently includes over 160 indicators of the food environment. The year and geographic level of the indicators vary to better accommodate data from a variety of sources. Some indicators are at the county level while others are at the State or regional level. The most recent county-level data are used whenever possible."