Morbid obesity is defined as a body mass index of 40 kg/m2 or more, or of 35 to 40 kg/m2 with significant medical problems related to body weight. Comorbidities include type 2 diabetes, coronary heart disease and hypertension. Weight loss reduces the comorbidities and improves long-term survival.
Morbid obesity is managed by lifestyle changes including exercise and diet and medication. Bariatric surgery is a treatment option in selected patients if they have not lost enough weight using non-surgical measures.
Surgical procedures aim to help patients lose weight by restricting the size of the stomach (for example, gastric banding or sleeve gastrectomy), or by decreasing the patient's capacity to absorb food (for example, Roux‑en‑Y gastric bypass or biliopancreatic diversion).