RecruitingBehavioural interventionStudy Comparing Acceptance and Commitment Therapy to Supportive Diabetes Counseling and a Waitlist Control for Eating Disorders in Type 1 DiabetesThe goal of this clinical trial is to test whether a new intervention works to treat eating disorders in type 1 diabetes. Participants are assigned to one of the following: (1) Acceptance and Commitment Therapy (ACT), (2) Supportive Diabetes Counseling, or (3) a 6-month Waitlist Control. Participants in the ACT and Supportive Diabetes Counseling conditions complete 12 sessions over 12-16 weeks and use their mobile phone between sessions to increase engagement and reinforce learning. The main questions are: Does treatment improve glycemic levels, eating disorder symptoms, diabetes management and diabetes distress? Does one treatment do better than the other? How do the treatments work, if they work, and for whom? Participants complete assessments that include wearing a continuous glucose sensor and activity watch, and get a blood draw to determine HbA1c. They also complete diagnostic interviews, surveys and computer tests of attention and things like heart rate and reaction time. These assessments help us better understand the types of changes that are happening and how they might influence health and well-being.