Picky Monster: Examining the Effects of Visual Reinforcements Through Gamified Avatars and Personalized Goal Setting on Reducing Sugar Consumption

High sugar consumption is a known risk factor for various diseases. While technological solutions for food decision-making and diet control have shown promise in maintaining user engagement and adherence to health goals, there is a lack of research on adapting visual reinforcement mechanisms and personalized daily consumption goals to reduce sugar intake. Our study aims to improve snacking behavior through positive and negative visual reinforcement. We created PickyMonster, a mobile app to track and gamify sugar intake to raise awareness and promote healthier habits. Personalized daily sugar goal is based on one’s physiological data, visually represented by a four-stage monster avatar. In a two-week field study involving 15 students with snacking habits, we evaluated PickyMonster’s effectiveness. Findings revealed that visual cues of gamified avatars helped decrease people’s sugar intake and improved their health literacy. Participants reduced sugar intake and expressed heightened awareness. The number of participants who indicated to prioritize total sugar as a purchasing factor has doubled post-study. Although negative visual reinforcement did not yield expected results, design implications are provided. This research advances technology-driven interventions for healthier eating and suggests integrating positive and negative visual cues for promoting sugar reduction during snacking through gamified avatars.