Promoting dietary self-efficacy through social support: An application to online weight-loss communities

An increase in the number of individuals trying to lose weight has enabled the development of online weight-loss support communities (Weight Watchers, Dukan, etc.). This research aims to study whether and how social support in these communities affects dietary self-efficacy to improve individuals’ food well-being. After an initial qualitative study with 25 community users, we formulated hypotheses and tested them in a quantitative study involving 335 users. The results show that social support contributes to dietary self-efficacy through two sequential mediators: identification with community members and motivation to comply with group norms. Our analyses also show that nutritional knowledge moderates the relationship between motivation to comply and dietary self-efficacy. The results of these two studies enrich the literature on online communities and allow us to suggest managerial recommendations for administrators of these communities and health professionals.