Data and Maps

Data on Access to Healthy Food and Health Impacts. PolicyLink and The Food Trust released a report, The Grocery Gap, that highlights the results of a review of more than 130 reports and articles on the issue of access to healthy food. Key findings include:

• Accessing healthy food is a challenge for many Americans—particularly those living in low-income neighborhoods, communities of color, and rural areas. In hundreds of neighborhoods across the country, nutritious, affordable, and high-quality food is largely missing. Studies that measure the availability of food stores and healthy foods in nearby stores find major disparities in food access by race and income and for low-density, rural areas. For example:
  • Low-income zip codes have 25 percent fewer chain supermarkets and 1.3 times as many convenience stores as middle-income zip codes. Predominantly black zip codes have about half the number of chain supermarkets as predominantly white zip codes, and mostly Latino areas have only a third as many.
  • Low-income neighborhoods have half as many supermarkets as the wealthiest ones and four times as many smaller grocery stores, according to an assessment of 685 urban and rural census tracts in three states. The same study found four times as many supermarkets in predominantly white neighborhoods compared to predominantly black ones.
  • Another multistate study found that 8 percent of African Americans live in a tract with a supermarket compared to 31 percent of whites.
  • Another nationwide analysis found that there are 418 rural “food desert” counties where all residents live 10 miles or more from the nearest supermarket or supercenter—20 percent of all rural counties.

• Better access corresponds to healthier eating. Studies find that residents with greater access to supermarkets or a greater abundance of healthy foods in neighborhood food stores consume more fresh produce and other healthful items.
  • African Americans living in a census tract with a supermarket are more likely to meet dietary guidelines for fruits and vegetables, and for every additional supermarket in a tract produce consumption rises 32 percent. Among whites, each additional supermarket corresponds to an 11 percent increase in produce consumption. This study used a large sample: 10,230 adults living in 208 urban, suburban, and rural census tracts in four states.
  • Adults with no supermarkets within a mile of their homes are 25 to 46 percent less likely to have a healthy diet than those with the most supermarkets near their homes, according to a study that used data from North Carolina, Baltimore, and New York City. A healthy diet was defined using two different measures: the Alternate Healthy Eating Index, which measures consumption of foods related to low risk of chronic disease, and a measure looking at consumption of fats and processed meats.
  • Proximity to a supermarket is associated with increased fruit consumption among food stamp recipients (based on a nationally representative sample). Similar patterns were also seen with vegetable consumption, though associations were not statistically significant.

• Access to healthy food is associated with lower risk for obesity and other diet-related chronic diseases. Researchers find that residents who live near supermarkets or in areas where food markets selling fresh produce (supermarkets, grocery stores, farmers’ markets, and so forth) outnumber food stores that generally do not (such as corner stores) have lower rates of diet-related diseases than their counterparts in neighborhoods lacking food access.
  • Adults living in neighborhoods with supermarkets or with supermarkets and grocery stores have the lowest rates of obesity (21 percent) and being overweight (60–62 percent). Those living in neighborhoods with no supermarkets and access only to convenience stores, smaller grocery stores, or both had the highest rates (32–40 percent obese; 73–78 percent overweight), according to a study of more than 10,000 adults.
  • The lack of supermarket access corresponds to higher rates of diet-related death in Philadelphia.

(See The Grocery Gap for a full analysis of the relationship between food access, diet, and health.)

Mapping Access to Healthy Food and Health Disparities. Some communities working to address the problem of access to healthy food have used maps to highlight disparities. For example, the map below shows that in low access, lower-income areas, residents travel longer distances to supermarkets than other residents in higher-income areas. Though Jefferson County is only 19 percent African American overall, in areas with low access to supermarkets the population is 68 percent African American.

Based on maps created by the Community Farm Alliance in 2006 and The Reinvestment Fund’s low supermarket access analysis. For more information on The Reinvestment Fund’s methodology, see www.trfund.com/financing/realestate/EstimatingSupermarketAccess-1pg.pdf.

Maps can also be helpful in making the case for the relationship between access to healthy food and health outcomes. The three maps of New York City below show that many areas with high supermarket need also have high percentages of residents consuming no fruits and vegetables, and high rates of diabetes and obesity.

Mapping Resources

There are existing resources that can be helpful in identifying local food access challenges:

The USDA has released a food desert locator that shows census tracts the agency considers food deserts. The Healthy Food Financing Initiative (HFFI) working group defines a food desert as a low-income census tract where a substantial number or share of residents has low access to a supermarket or large grocery store:

• To qualify as a “low-income community,” a census tract must have either: 1) a poverty rate of 20 percent or higher, or 2) a median family income at or below 80 percent of the area's median family income.
• To qualify as a “low-access community,” at least 500 people and/or at least 33 percent of the census tract's population must reside more than one mile from a supermarket or large grocery store (for rural census tracts, the distance is more than 10 miles).

The USDA also has a food environment atlas that provides county-level statistics on food choices, health and well-being, and community characteristics.

The Reinvestment Fund’s helpful PolicyMap shows Low Access Areas, defined as areas that are underserved by full-service supermarkets, and have significant grocery retail leakage and demand. This PolicyMap tool accounts for population density and car ownership in determining the areas that are underserved. It also identifies clusters of underserved low-access census tracts, which provides information about need and potential market viability.

Other organizations such as Social Compact, LISC MetroEdge, and Mari Gallagher Research and Consulting Group have conducted assessments of local food environments. In addition, many community-based organizations conduct local community food assessments.

The PolicyLink chapter, Community Mapping for Health Equity Advocacy, also includes helpful mapping tips and information.