Excessive preoccupation with self-image (or identity) is regarded as a factor contributing to the proliferation of food disorders, especially among young women. This paper models how self-image and peer effects influence health-related behaviours, specifically food disorders. We empirically test our claims using data from the Eurobarometer Survey. Our findings suggest that the larger peers’ body mass, the lower the likelihood of being anorexic. Self-image is correlated with body weight. We use several definitions of peers’ body mass, and find that all are negatively associated with the likelihood of women being thin or extremely thin.