Gamified Challenges in Online Weight-Loss Communities

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. In this paper, using the data from a leading online weight-loss community, we study the effect of gamified challenges on the weight-loss outcome. We employ a dynamic model, using a system generalized method of moments estimator combined with an inverse probability weighting approach, to address endogeneity issues. 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 kilograms (kg) by participating in at least one challenge a month. We demonstrate that not all gamified challenges are equally effective; 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. We discuss, as a potential underlying mechanism, the role of leaderboards to induce social comparison and motivate (discourage) users in exercise (diet) challenges. Our findings have implications for designing gamified systems with competition elements in online weight-loss communities.