INS and obesity due to melanocortin 4 receptor deficiency: OAGB excluding 150 cm of the small intestine performed among patients with type 2 diabetes and obesity of the first degree (BMI 30–35 kg/m2), results in a complete withdrawal of insulin or a significant reduction in insulin doses and oral hypoglycaemic medication doses and, in more than half of patients, in complete recovery from type 2 diabetes.