This project is a randomized controlled trial of iACT, a novel mHealth intervention for eating disorders in type 1 diabetes (ED-T1DM). Participants will be 128 T1DM patients between the ages of 16-45 with binge-purge EDs, including threshold and subthreshold bulimia nervosa, binge eating disorder and purging disorder. Participants will be randomized to either iACT or Usual Care, and complete assessments at baseline and every 3 months for 9 months. The primary outcome of interest is glycemic control as assessed by continuous glucose monitoring. Other outcomes include HbA1c, eating disorder symptoms, diabetes self-management and diabetes distress. In addition to examining clinical outcomes, this study tests biobehavioral mechanisms of change and predictors of treatment response. Process of change assessments focus on flexible responding to pathology-relevant stimuli and early improvement in glycemic control affecting executive function. The primary site is Duke University Medical Center. The Miriam Hospital is a secondary site.