The aim of this case study is to illustrate the importance of collaborative care as part of Maudsley Anorexia Nervosa Treatment for Adults (MANTRA). Mothers are often at the foreground of providing support within the family. However, fathers have the potential to play a profound role. In this paper, we describe a patient with anorexia nervosa treated with the MANTRA. The formulation of this case included autistic spectrum traits in both the father and daughter leading to social isolation. We describe how the family members were engaged into treatment and how paternal support was used to promote social connection and an improved quality of life in the daughter. Some details of the case have been altered to maintain confidentiality.