Inclusion criteria:  sufficient German language skills (C1) permanent internet access during the study period meeting the diagnostic criteria for Bulimia Nervosa according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5)  Exclusion criteria:  current severe depressive episode acute suicidality comorbid bipolar disorder or psychotic disorders acute substance dependence current psychotherapy or pharmacotherapy for eating disorders Body Mass Index (BMI) below 18.5