FlexED: National Substudy

Primary outcomes

1. Change from Baseline in the Body Image - Acceptance and Action Questionnaire (BI-AAQ)-5

   Time frame: Baseline, Week 4, Week 8, Week 12

   Self-report measure of body-image psychological flexibility. The measure consists of 5 items that ask about the degree to which thoughts and feelings about the body interfere with living. Higher scores indicate greater flexibility/adaptability.

2. Change from Baseline in the Comprehensive Assessment of Acceptance and Commitment Therapy Processes -10 (CompACT-10)

   Time frame: Baseline, Week 4, Week 8, Week 12

   A 10-item measure of psychological flexibility as a multidimensional construct with subscales of Openness, Awareness and Engagement. Higher scores indicate greater flexibility/adaptability.

3. Change in Weight Concern Scale Score

   Time frame: Baseline, Week 8, Week 12

   5-item measure of weight concerns (worry about weight, fear of weight gain, dieting history, importance of weight, fear of fatness). Elevated scores have been associated with the development of eating disorders.

4. Change from Baseline in the Eating Disorder Examination - Questionnaire Short Form (EDE-Q-SF)

   Time frame: Baseline, Week 8, Week 12

   Questionnaire format of the clinician-administered interview assessing eating disorder symptom severity, producing a Global score (main outcome) and 4 Subscale scores: Restraint, Eating Concerns, Weight Concerns, Shape Concerns. Higher scores indicate greater symptomatology.

5. Acceptability of the Intervention

   Time frame: 8 weeks

   Session completion rates