Factors associated with weight change in social media: from correlations to causal analyses

Abstract

Online health communities (OHC) represent today a major source of information for health-related issues, providing an environment where people with similar conditions can connect and exchange social support, which is recognized as an important element of successful health-related behavior change. However, most of the existing studies only look at the effect that offline social support has. This thesis fills gaps in the literature by proposing a framework to study the causal effect that receiving social support in an online weight loss community has on (i) the probability of the user to stay in the community, and, more importantly, on (ii) the weight loss reported by the user. Further, we study properties of a Reddit OHC and show its mechanisms to provide social support. We found that the nature of social support manifested in Reddit as well as the user engagement and the topics discussed are indicative of weight change. Our results show the potential of OHCs to aid health professionals