In 2025, the Seoul Metropolitan Government implemented The Less Sweet Expedition, a 90-day mobile-based low-sugar dietary program designed for elementary school children and their caregivers to address excessive sugar intake among children. Operated through the Wrist Doctor 9988 application, the program recruited 30,128 participants, of whom 14,576 completed the final verification process. This study examined the program’s operational outcomes and participant effects, with a particular focus on changes in sugar-related knowledge, attitudes, and behaviors.
The findings showed statistically significant improvements across participants’ overall sugar-related knowledge, attitudes, and behaviors. In particular, the parent-child co-participation structure—through which parents and children jointly checked the sugar content of foods and discussed snack choices—functioned effectively in establishing low-sugar dietary routines within the household. These results suggest that the program served not only as a mobile health intervention but also as a family-based behavioral strategy for promoting healthier eating practices among children.
At the same time, several limitations were identified. The repetitive mission structure over the 90-day intervention period appeared to reduce children’s interest in the later stages of participation. In addition, inconvenience in snack-entry processes, insufficient feedback mechanisms, and the lack of child-perceived rewards were noted as key operational weaknesses. These findings indicate that sustaining engagement in child-centered mobile health programs requires not only informational and behavioral components but also user-friendly design and developmentally appropriate motivation systems.
Overall, the program demonstrates meaningful potential as a mobile-based public health model for improving children’s dietary behaviors. Future refinement through more diverse content, improved input convenience, stronger reminder systems, and child-tailored reward mechanisms may further enhance its effectiveness and support its development into a representative mobile health policy model for Seoul.