Physical Activity in the Prevention and Treatment of Eating Disorders On the one hand, excessive or insufficient physical activity is a phenomenological feature and an important etiological factor in eating disorders. On the other hand, healthy and adaptive physical activity has the potential to support the effectiveness of preventive and therapeutic interventions for eating disorders. Research findings confirm the usefulness of interventions focusing on physical activity as an add-on to psychotherapy. Professionally planned and accompanied interventions of this kind are not counterproductive or dangerous but can have a positive effect on the treatment outcome. The current state of research allows a preliminary formulation of guidelines to embed physical activity interventions into evidence-based treatment approaches. The focus of such interventions lies on the reduction of unhealthy, excessive physical activity and the promotion of flexible physical activity.