Beyond one-shot nudges: the effects of repeated interventions for healthier online meal ordering

Digital nudges offer a promising approach to promote healthier food choices in online meal ordering, but their effects over repeated exposures and across multiple decisions are undertested. We explored how two nudges, Just-in-time feedback and Assortment, individually and in combination, may affect healthy food choices in a three-day experiment using a mock online meal ordering platform. Participants (N = 154) were randomly assigned to Feedback, Assortment, Combined, or Control conditions and completed daily lunch orders hypothetically, each including a main dish, side dish, and drink. Across conditions, healthy ordering increased from Day 1 to Day 2 before declining in the Control and Feedback groups by Day 3. The Combined condition, integrating both structural (Assortment) and moment-of-choice (Feedback) approaches, successfully attenuated this decay, resulting in a 24% higher composite health score compared to Control at Day 3 (d = 0.66, p = 0.04). Component-level analysis revealed that while main dish choices converged across conditions by Day 3, the sustained effectiveness of the Combined nudge was driven by improvements in side dish and drink selections. These findings highlight the potential of multifaceted digital nudges to sustain healthier choices over time in online food environments.