The USDA studied communities with limited access to affordable and nutritious food. They found that a relatively small percentage of households lack access to a supermarket or large grocery store: 2.3 million households in the United States (2.2%) live more than a mile from a supermarket and do not have access to a vehicle. In addition, low-income individuals with limited access spend more time, on average, traveling to grocery stores. Other findings:
· 5.7% of all households report that they do not always have the food they want or need because of access limitations. This number would include those without access to a store nearby, but also those with trouble getting to a store (regardless of distance).
· In urban areas, 10.1 million low-income individuals live more than 1 mile from a supermarket. Within urban clusters, 1.4 millions individuals live more than 1 mile from a supermarket. In rural, low-income areas, 13.7 million residents (85.7%) were within 10 miles of a supermarket, 1.9 million were 10 to 20 miles from a supermarket (11.7%) , and 2.6% were more than 20 miles from a supermarket.
http://www.ers.usda.gov/Publications/AP/AP036/