In 2001, the last supermarket in Chester, Pa., closed. By the time a new market opened in 2013, the city was classified by the U.S. Agriculture Department as a food desert, an area without easy access to fresh fruits, vegetables, and other healthy food.

Eliza Whiteman, a second-year doctoral student in PennDesign’s Department of City and Regional Planning, was curious about how the low-income residents of Chester acquired food. She’d read research on people living in food deserts and their access to food resources based on spatial measures, but wondered what other factors have an influence on healthy food acquisition, including timing of welfare benefit distributions and adequate resources to purchase food.                                                    

To help answer this question, she used data from the Chester Food Shopping Study, a research project led by Amy Hillier, associate professor in city and regional planning in PennDesign. Between June 2013 and August 2015, participants in the study completed surveys on their food shopping behaviors and attitudes, food security, daily diets, and health status.

Whiteman found that study participants—the vast majority of whom received federal food assistance benefits through the Supplemental Nutrition Assistance Program (SNAP)—purchased less food overall, as well as less nutritious food, by the end of each month as the length of time increased from the date of their SNAP disbursements.

With a population of 35,000, one-third of Chester residents live below the federal poverty level and receive SNAP benefits once a month within the first 10 business days.

Whiteman’s study showed that the nutritional quality of their food not only changed over the course of the month, but it varied between items purchased at stores and those acquired at food pantries and other emergency sites.

“There was decreasing spending on low-calorie foods and U-shaped spending on high-calorie foods over the month, as well as a higher proportion of low-calorie foods among the study participant’s food pantry acquisitions,” Whiteman says.

Her findings are described in the paper, “When Is Food Insecure? Identifying Temporal Purchasing and Nutritional Patterns Among SNAP and Food Pantry Users.”

Whiteman, who is also a Penn Institute for Urban Research-affiliated student, co-authored the paper with Hillier, her mentor and a faculty fellow at Penn IUR.

Whiteman says that her research has policy and programming implications for federal and non-profit food assistance programs.

“A more nuanced measure of food access that accounts for the role of timing in food insecurity and nutrition could provide insight to better design SNAP distribution and other hunger alleviation interventions with the goal of helping smooth cyclic food insecurity and nutritional adequacy,” she says.