An agent-based model of income inequalities in diet in the context of residential segregation

Abstract

Background: Low dietary quality is a key contributor to obesity and related illnesses, and lower income is generally associated with worse dietary profiles. The unequal geographic distribution of healthy food resources could be a key contributor to income disparities in dietary profiles.

Purpose: To explore the role that economic segregation can have in creating income differences in healthy eating and to explore policy levers that may be appropriate for countering income disparities in diet.

Methods: A simple agent-based model was used to identify segregation patterns that generate income disparities in diet. The capacity for household food preferences and relative pricing of healthy foods to overcome or exacerbate the differential was explored.

Results: Absent other factors, income differentials in diet resulted from the segregation of high-income households and healthy food stores from low-income households and unhealthy food stores. When both income groups shared a preference for healthy foods, low-income diets improved but a disparity remained. Both favorable preferences and relatively cheap healthy foods were necessary to overcome the differential generated by segregation.

Conclusions: The model underscores the challenges of fostering favorable behavior change when people and resources are residentially segregated and behaviors are motivated or constrained by multiple factors. Simulation modeling can be a useful tool for proposing and testing policies or interventions that will ultimately be implemented in a complex system where the consequences of multidimensional interactions are difficult to predict.

Figure 1

Income differences (with 5th–95th percentiles) healthy diet and median healthy diet under various segregation scenarios

Figure 2

Income differences (with 5th–95th percentiles) in healthy diet and median healthy diet for index scenario S6 (ref) and experiments that incorporate differences in food preferences by income and differences in price between healthy and unhealthy food stores ref, referent experiment (S6)

Figure 3

Income differences (with 5th–95th percentiles) in healthy diet for the desegregated (random) and segregated (index scenario 6) scenarios ref, referent experiment (S6)