The FRESH zone is developed based on Supermarket Need Index (Food Bank in New York n.d.), Supermarket Need Index is based on highest levels of diet related diseases and largest population with limited opportunities to purchase fresh food (Going to Market, NYC Department of City Planning, 2008).

The Supermarket Need Index uses the following measures: high population density, low access to a car at the household level, low household income, high rates of diabetes, high rates of obesity, low consumption of fresh fruits and vegetables, low share of fresh food retail, capacity for new stores.

Some indicators, such as “Consumption of Fruits and Vegetables” and “Diet-related Diseases” have boundaries that cover large areas.

The department also used Zip codes to find access to Fresh Food Retailers. The usage of Zip Code to define area is proven to be limited. Areas defined by Zip Codes do may also produce large measurement error (Mark, Anselin & Grubesic, 2011).