Participants are assigned at random to either the IPT or teen health education program. All participants have a 1- to 1 1/2-hour individual session with a therapist, followed by 12 weekly group sessions of 1 1/2 hours each in their assigned program. They are assessed at the end of the program with questionnaires and body measurements. They return to the clinic after 6 months for body measurements, blood test, DXA scan, questionnaires, interview and a test meal, and again at 1 year for body measurements, questionnaires and a DXA scan.