The purpose of this study was to test if an ACT group intervention focusing on body image reduces eating disorders symptoms and reduces care consumption in patients treated at a specialised eating disorder unit.

The study is an RCT in which the ACT-intervention is compared to treatment as usual. The trial started in 2010, and randomisation of patients continued until 2014, and follow-ups was completed in 2016.

According to analysis of power, a total of 120 patients needed to be included, 60 in each arm. Patients eligible for the interventions were invited to participate after their clinician reported them to the head investigator. The head investigator sent a letter to the patients with information on the study. The clinician then asked the patient if the letter had been read. If the patient wanted to participate, he/she was invited to an information and assessment meeting. The head investigator made sure that the patient understood the information, and what each study arm might mean for the patient when participating. Consent to participate was collected both verbally and in writing. At this meeting the patient received an envelope which contained the randomisation outcome. The patient then received information regarding the continued treatment according to which research arm he/she was to participate in.

The participants randomised to treatment as usual continued with the treatment as planned before enrolment.

Participants in the intervention arm started the group intervention consisting of 12 sessions over a period of three to four months. The intervention also included one individual meeting with the group-leaders before and one after the intervention. The intervention is a manualised application of the book "Lev med din kropp" [Live with your body]. Participants who were in need of further care after the intervention were offered continued treatment accordingly at the clinic.

If a participant chose to terminate the intervention, or deteriorated during the intervention to the point that other treatment was needed, further treatment was agreed upon in dialogue with the patient. If needed, further assessment and physical examination was conducted in accordance to the clinics standard procedures.

Data was collected at four times for all participants. At treatment start and end, and follow-up at 12 and 24 months after inclusion. At each time, the participants were prompted to fill in five different self-assessment forms.

Inclusion Criteria:

• Diagnosed with an eating disorder according to DSM-IV (APA, 1994)
• Enrolled as a patient at Eriksbergsgarden, a clinic in Sweden offering specialized care for patients with an eating disorder
• Attained a somewhat regular eating pattern consisting of at least three meals per day

Exclusion Criteria:

• Having physical or psychiatric complicating factors of such severity that these conditions needed to be addressed during the treatment period (12 weeks).