The Kindness of Commenters: An Empirical Study of the Effectiveness of Perceived and Received Support for Weight-Loss Outcomes

Social media-based online communities are becoming increasingly popular for various social interactions, including those for healthcare and health-related activities. The benefits from these activities, however, are constrained by how a platform is designed, as a platform's design defines what activities can be done and how individuals can engage and interact on the platform. In this study, we focus on weight-loss communities and social tools that facilitate social communication and establish a variety of relationships between users. In particular, we examine the effectiveness of one-way and two-way social relationships on individuals' weight-loss management. Drawing from theories of social support, social reciprocity, and social indebtedness, we use two-way friendship relationships to proxy perceived support and one-way commenting relationships to proxy received support and conjecture that they work through different pathways. We find, through empirical analyses, that both types of social relationships as well as self-monitoring are effective in promoting weight loss, but perceived and received support have different impacts. Whereas both perceived and received support are positively related to weight-loss outcomes, the effect of received support is found to be higher than that of perceived support and the difference is statistically significant. Moreover, we find that received support is positively associated with self-monitoring behaviors, whereas perceived support is not. These findings provide insights for platform providers to improve the social design aspect of online services and for healthcare practitioners in their efforts to advise individuals on weight self-management. Our results also can be used to design and implement more effective online interventions.