Mapping Healthy Food Lanscapes for WIC Participants

Background

As part of a natural experiment to evaluate the impact of the WIC voucher changes that will go into effect in October 2009, we collected baseline information about the food environment and food purchases of WIC participants in two predominantly low-income areas in North Philadelphia. One of the areas is predominantly African-American; the other is predominantly Puerto-Rican. We adapted the Nutrition Environment Measure for Stores (NEM-S) to measure the availability of healthy foods in the 150 stores within the study area and administered a 15-minute survey about where WIC participants shop and what foods they purchase with 200 WIC participants using handheld computers.

Methodology

We used vector GIS methods to map and analyze where WIC participants live relative to where they shop. We used raster GIS to map and analyze healthy food scores for individual stores and to create a healthy food “landscape.” Finally, we used cartographic modeling techniques to identify possible sources of “friction” that prevent WIC participants from shopping at the closest stores with the healthiest foods.

Expected Results

We expect to find that WIC participants do not always shop at the closest food store or the food stores with the greatest availability of healthy foods.

Discussion

“Access” to healthy foods requires having those foods available and affordable. But barriers such as transportation, perceived neighborhood boundaries, cultural and language differences, and fear of crime likely present additional challenges to accessing healthy foods for residents of low-income residents