摘要:Efforts to encourage Americans to improve their diets and to eat more nutritious foods presume a wide variety of these foods are accessible to everyone. But for some Americans and in some communities, access to healthy foods may be limited. Policies to improve access to healthful foods have been implemented at Federal, state and local levels of government. Past research has focused on ways to determine whether and what portions of the population experience limited access to healthful food, but very few studies have attempted to estimate food access for the entire nation. This paper describes refined methods for measuring food access on a national level and for specific population characteristics. It also provides updated estimates of the number of people in the U.S. with limited access to healthy and affordable food. Population data from the 2010 Decennial Census, income and vehicle access data from 2006-2010 American Community Survey, and a 2010 composite list of supermarkets were used. Distance to the nearest supermarket has not changed greatly for the population since 2006. New estimates also show that half of the U.S. population lives within 2 miles of three supermarkets, with a median distance to the third nearest supermarket of 1.9 miles.