This study explores the attributes and level of influence of Twitter users and how different types of network influencers emerge as agenda setters on WeightWatchers’ free diet program for teens. This study collected and analyzed data through the computer-assisted content analysis program and network analysis software, NodeXL. Celebrities on social networking sites were found to have greater centrality, but health advocates (against the Weight Watchers’ teens free program) also have the role of influencers. The WeightWatcher brand online community includes health advocates, researchers, activists, and non-profit organizations. While this study revealed that Twitter facilitated the emergence of a brand community sharing certain characteristics with public spheres, it also illustrates the degree to which the construction of public health frames by health advocates competes with celebrity influencers with greater levels of influence.