Modified Retail Food Environment Index

The Modified Retail Food Environment Index (mRFEI) is a spatial measure, developed by the U.S. Centers for Disease Control and Prevention, that summarises the retail food environment of a small area as the percentage of healthy food retailers among all food retailers in that area. For each census tract, the CDC counted healthy retailers (supermarkets, larger grocery stores, supercenters and produce stores) and less-healthy retailers (fast-food restaurants, convenience and small grocery stores) from national business databases, then expressed the index as healthy divided by all, times 100. Released in the 2011 Children's Food Environment State Indicator Report with census-tract maps for every U.S. state, the mRFEI offers a scalable, secondary-data way to flag food deserts (no retailers) and food swamps (dominated by less-healthy outlets) and to study how the food landscape relates to diet and obesity.