Smartphone supports help form habits for taking pre-meal photos
Supporting Habit Formation in Pre-Meal Photo Capture: A Longitudinal Study of Behavior Change Techniques
Human-Computer Interaction
Summary
Taking a photo before eating can be a good habit but is hard to remember before the first bite. The authors studied how smartphone features can help people remember to take these photos regularly. They tested prompts, reminders of past successes, and social support over five weeks with 54 people. They found that support helped people form habits and remember more easily, but over time participants used fewer active features as the habit became natural. Some still liked having support available and combined different strategies to keep the habit going.
What this means in practice
- •For mobile app developers: Design smartphone apps for photo tracking that adapt prompts and social supports to help users build and maintain pre-meal photo capture habits.
- •For digital health product teams: Develop habit-supporting tools that maintain consistent user engagement for dietary monitoring by combining automatic and social support features.
Authors
Jun Fang, Yueying Suo, Yuntao Wang, Susu Wang, Xiaoyu Yang, Qiqi Liu, Chuangyu Ding, Yuanchun Shi
Abstract
Pre-meal photo capture is lightweight only with a smartphone, yet habit formation requires repeatedly initiating and completing the action within the narrow window before the first bite. We examine how supports based on behavior change techniques can shape capture adherence, perceived habit, and support needs over time. Using a participant-informed selection process, we implemented three smartphone supports targeting Prompts/cues, Focus on past success, and Social support. We evaluated them in a five-week field study with 54 participants, spanning support, withdrawal, and reinstatement, followed by interviews and a three-week follow-up. Across 4,945 main meals, 63.9\% were confirmed pre-meal captures, and adherence was broadly maintained across phases. Perceived automaticity and spontaneous remembering improved mainly during initial support. As capture became more familiar, participants combined spontaneous remembering with deliberate strategies, reduced active feature use while continuing to value support availability, and carried the practice forward through accumulated records, familiar tools, and chosen relationships. These findings frame BCT support for pre-meal photo capture as a configurable arrangement. Systems should preserve a predictable capture pathway while adapting when, how, and through whom support remains available.