In January 2010 a new interdisciplinary clinic (STOMP) was created to provide care for children and adolescents with severe 'complex' obesity. As part of the program, a subset of adolescents undergo bariatric surgery. There is a paucity of literature evaluating outcomes of children and adolescents participating in a 'clinical' setting and even fewer reports of outcomes of severely obese pediatric patients. Previously, the investigators evaluated clinical outcomes of children with craniopharyngioma and hypothalamic obesity attending an outpatient interdisciplinary program at SickKids (The Comprehensive Care Clinic for Children with Central Tumours) and found significant benefit to those attending, including reduction of weight gain (or weight loss), improved psychosocial functioning, and increased care satisfaction. STOMP is a natural extension of this program, incorporating some core elements (e.g., interdisciplinary team, frequent visits, individualized care plans for medically-complex adolescents) and building on other aspects, such as increased psychosocial intervention; involvement of a key worker (nurse practitioner) to support families; provision of continuity of care with other health providers in all settings, community services and schools; a more diverse patient population; and group support sessions. Evaluation of the outcomes of this clinic is needed to inform best practice for children and adolescents with severe complex obesity