31 families of female adolescents affected by anorexia nervosa (AN) and 20 of girls with emotional and behavioral disorders participated in a semi-standardized videotaped game: the Lausanne Trilogue Play (LTPc). We aimed to clarify if there is a typical AN family profile and if the LTPc procedure could predict the risk of developing AN. We confirmed that AN families exhibit dysfunctional alliances. Particularly because of the difficulty of the three members to be available to the interaction at least with their body (participation) and to comply with the role expected at each stage of the game (organization). Moreover, these families show a significant worse functioning, especially regards to the mother-daughter phase of the game, in focal attention and affective contact functional levels, while in triadic and couple phases they present lower scores than comparison group in all functional levels. Furthermore, we found that LTPc may predict the possibility of belonging to a family with a daughter with AN rather than one whose daughter has a different disorder. Therefore, LTPc would allow clinicians foresee the risk of developing AN and tailoring the most suitable therapeutic intervention and finally see its effectiveness using LTPc for later follow-up video feedback sessions.