Gamified Challenges in Online Weight-Loss Communities
研究在线减肥社区中游戏化挑战对减肥效果的影响，发现参与挑战能显著减重0.742公斤，且有效的挑战应避免数字体重目标、聚焦运动行为目标并保持较大活跃群体规模。
Gamified challenges, one of the most popular features of online weight-loss communities, enable users to set weight-loss goals and compete with other challenge participants via leaderboards. Using the data from a leading online weight-loss community, we study the effect of gamified challenges on the weight-loss outcome. Our findings indicate that participation in gamified challenges has a positive and significant effect on weight loss. We found that, on average, the participants achieved a weight loss of 0.742 kg by participating in at least one challenge a month. We found that effective challenges do not include a numeric weight goal (e.g., lose 5 kg), focus on exercise-only behavioral goals, and have a large active group size. Further, the results show that the absence (presence) of a numeric weight goal benefits users in exercise (diet) challenges. Moreover, a small active group size can help (hurt) users in exercise (diet) challenges. Our results suggest that gamification elements that induce competition should be used with caution in goal-setting environments, especially when gamifying dietary goals. Online weight-loss communities can recommend a useful combination of numeric weight goals, behavioral goals, and an optimal number of participants in each challenge to induce an encouraging level of social comparison.