Development and Feasibility Study of Sustainable ePlate: A Web-Based Serious Game for Multidimensional Sustainable Healthy Diet Interventions in Schools

Background: School-based sustainable and healthy diet (SHD) interventions often inadequately capture the multidimensional nature of sustainability, with socioeconomic and cultural dimensions frequently underrepresented. While digital interventions can facilitate the integration of multiple SHD components, maintaining user engagement remains a persistent challenge that can compromise intervention effectiveness. Digital serious games represent a promising intervention strategy that can address both limitations by delivering multidimensional SHD content through interactive and engaging learning, while enabling real-time behavioral monitoring. Objectives: To assess the feasibility, as well as the acceptability and user experience of “Sustainable ePlate”, a web-based serious game for multidimensional SHD educational interventions in schools, during school-based sessions. Methods: Sustainable ePlate integrates food-level sustainability indicators into a scaffolded nine-challenge serious game. Challenges are presented through the healthy eating plate structure, while addressing eight food-level sustainability indicators transformed into 1–5 ordinal game scores. A database of 138 food items was developed from publicly available LCA and TCA databases. The game design draws on established learning theories implemented through progressive challenge sequencing, tiered feedback, and social features. Feasibility was assessed in guided school sessions in Northern Greece using the eGameFlow questionnaire and system in-app metrics. Results: The assessment sample comprised n = 59 students from two secondary schools, of whom n = 57 completed the eGameFlow questionnaire. Mean overall enjoyment was 82.54 ± 16.33%. Mean session duration was 22.39 ± 12.68 min. Across all sessions, 6003 food selections were recorded, with 5179 correct and 824 incorrect placements, corresponding to an 86.27% placement accuracy rate. In-app metrics indicated strong technical feasibility, with all sessions completing the full game sequence. Behavioral metrics demonstrated active interaction, characterized by placement interval duration, hesitation times, and high placement accuracy. Conclusions: Sustainable ePlate demonstrated feasibility and a positive user experience as a school-based serious game for multidimensional SHD education, and as a research platform for capturing in-app behavioral metrics. Further studies are required to assess its educational effectiveness in improving knowledge, attitudes, and practices related to sustainable healthy diets through pre–post design interventions.