Abstract

Abstract for: Beyond the Intervention: Mapping the Feedback Dynamics That Shape Dietary Behavior Following a Produce Prescription Program in Rural Mississippi

Introduction Despite growing investment in Food is Medicine (FIM), knowledge gaps remain in understanding the sustainability of dietary behavior change following intervention completion. This study leverages insights from semi-structured interviews conducted with Delta GREENS produce prescription (PRx) randomized controlled trial (RCT) participants at program completion (12 months) and three months post-program (15 months) to develop a causal loop diagram (CLD) examining the feedback mechanisms influencing post-program fruit and vegetable (F&V) intake and the degree to which it is sustained.
Approach We use an interview-based mental model elicitation approach to identify key variables, causal relationships, and emergent feedback loops from participant narratives at 12 months (n=20) and 15 months (n=15 of 20 to date). Themes from post-program interviews iteratively inform CLD development, and broader environmental factors, including food cost, household income, and fresh F&V retail access, are treated as exogenous contextual drivers.
Results The preliminary CLD identifies seven feedback loops - two reinforcing and five balancing - shaping post-program F&V intake. Erosion dynamics outweigh sustaining forces, which are driven by the weakening of fresh F&V routines, convenience-driven substitution, and budget-driven shifts toward lower cost processed foods, interacting with structural constraints in the food environment.
Discussion These compounding feedback dynamics, temporarily buffered by the produce prescription program, shape the sustainability of post-program F&V intake. Post-program fresh F&V access, affordability supports, and cooking routine maintenance emerge as potential leverage points. The finalized CLD will provide a foundation for future simulation modeling to evaluate and prioritize leverage points that support sustained dietary behavior change.

Introduction	Despite growing investment in Food is Medicine (FIM), knowledge gaps remain in understanding the sustainability of dietary behavior change following intervention completion. This study leverages insights from semi-structured interviews conducted with Delta GREENS produce prescription (PRx) randomized controlled trial (RCT) participants at program completion (12 months) and three months post-program (15 months) to develop a causal loop diagram (CLD) examining the feedback mechanisms influencing post-program fruit and vegetable (F&V) intake and the degree to which it is sustained.
Approach	We use an interview-based mental model elicitation approach to identify key variables, causal relationships, and emergent feedback loops from participant narratives at 12 months (n=20) and 15 months (n=15 of 20 to date). Themes from post-program interviews iteratively inform CLD development, and broader environmental factors, including food cost, household income, and fresh F&V retail access, are treated as exogenous contextual drivers.
Results	The preliminary CLD identifies seven feedback loops - two reinforcing and five balancing - shaping post-program F&V intake. Erosion dynamics outweigh sustaining forces, which are driven by the weakening of fresh F&V routines, convenience-driven substitution, and budget-driven shifts toward lower cost processed foods, interacting with structural constraints in the food environment.
Discussion	These compounding feedback dynamics, temporarily buffered by the produce prescription program, shape the sustainability of post-program F&V intake. Post-program fresh F&V access, affordability supports, and cooking routine maintenance emerge as potential leverage points. The finalized CLD will provide a foundation for future simulation modeling to evaluate and prioritize leverage points that support sustained dietary behavior change.