This is a study testing whether an online Multifamily Guided Self-Help Family Based Treatment (FBT) for Anorexia Nervosa in adolescents aged 12 to 17 is acceptable and useful to families. This online Multifamily Guided Self-Help version of FBT consists of 12 weekly 60-minute telemedicine groups made up of parents from 4-5 families of young people with AN, coupled with access to an online guided self-help platform over the course of 6 months. The feasibility of online Guided Self-Help Family-Based Treatment for Anorexia is unknown, and the investigators hope to identify an adequate treatment for those who do not have access to in-person FBT.

Previous research has shown that Family-Based Treatment (FBT) is an effective treatment for Anorexia Nervosa. In the first Phase of FBT, parents are encouraged to take charge of the process of renourishing their child with Anorexia. Then, once the young person with Anorexia becomes better nourished and is managing to eat in a more sustainable way, the treatment moves to Phase 2. In Phase 2 of FBT, the focus is on helping parents to step back and support their child to regain their independence around eating. Once this happens, the treatment moves to Phase 3, where the family begins to move forward with their lives in a normal way, no longer focused on the eating disorder.

The investigators hope to learn whether an adaptation of FBT, called online Multi-Family Guided Self-Help FBT, is feasible and acceptable for families of young people with Anorexia.

The 'Self-Help' aspect of the treatment consists of a series of educational videos about how to help a child with Anorexia, which parents watch on an online platform. The 'Multifamily' and 'Guided' aspects of the treatment consists of weekly meetings by Zoom for a group of parents of young people with Anorexia, with a facilitator present to guide a group discussion around whether parents feel they understood the content of the videos and whether the content is helpful.

Inclusion Criteria:

1. Adolescent participants are 12-17 years of age
2. Adolescent participants live with a family (some families may contain only one parent)
3. Family members fluently speak and read English and have access to a computer with internet
4. Adolescent participants meet DSM-5 criteria for AN
5. Adolescent participants' IBW above 75%
6. Adolescent participants are medically stable for outpatient treatment according to the recommended thresholds of the American Academy of Pediatrics and the Society of Adolescent Medicine

Exclusion Criteria:

1. Associated physical illness in any form that necessitates hospitalization of the adolescent with Anorexia
2. Psychotic illness in any form, mental retardation, autism, or any other mental illness in the adolescent or parents/ carers that would interfere with the use of psychotherapy.
3. Current dependence on drugs or alcohol in adolescent or parents.
4. Physical conditions (e.g. diabetes mellitus, pregnancy) in adolescent known to influence eating or weight
5. Participants and family members do not have an adequate understanding of spoken English and are not able to speak and read English in order to participate in family therapy and the assessments.
6. Current weight is less than 75% of expected weight given age and height.