Years of Data Used
USDA Food Environment Atlas, Map the Meal Gap from Feeding America
From the United States Department of Agriculture (USDA):
The Atlas assembles statistics on three broad categories of food environment factors:
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 diet
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.
Using the annual USDA Food Security Survey, Feeding America (Map the Meal Gap) models the relationship between food insecurity and other variables at the state level and, using information for these variables at the county level, we establish food insecurity by county.
Gundersen, C., E. Waxman, E. Engelhard, A. Satoh, & N. Chawla. Map the Meal Gap 2013: Food Insecurity Estimates at the County Level. Feeding America, 2013.
This measure cannot be further stratified as it is, since it is an index constructed out of two separate measures. However, you can view data on food access at the census tract level in the Food Access Research Atlas from the USDA here: http://www.ers.usda.gov/data-products/food-access-research-atlas/.aspx#.VDanVhbupZ4
In addition, Map the Meal Gap not only provides measures of overall food insecurity by county, but also measures of food insecurity among children on the same website.
Another way to access food environment data is through the Community Commons Health Equity Data Report. Data by race and census tract can be found for most communities. Note that you will need to login to access this report, but registation is free for all.