Metabolic syndrome is a cluster of cardiometabolic risk factors that cause some complications. Each component of the syndrome needs to be treated. For this purpose, anti-hypertensive, anti-diabetic, and anti-lipidemic agents are used, but weight control plays a key role in treatment. Exercise, reduction of daily calories with diet and increasing physical activity play a role in the control of body weight. Various medical treatments have been tried, but they have not been very effective. The most effective way is still surgery. Although there is no definite accepted definition of metabolic surgery, it can be defined as surgical interventions to treat metabolic syndrome. The general perception in bariatric surgery is that type 2 diabetes enters remission due to patients’ weight loss. After the operation in these patients, blood sugar control has been shown to be achieved while patients are still in the hospital. It has been understood that the gastrointestinal system plays an essential role in glucose homeostasis, and its mechanisms have been tried to be revealed. The foregut hypothesis and the hindgut hypothesis have been suggested. A hindgut surgery like a duodenal switch has been shown to improve insulin sensitivity and glucose homeostasis without causing a hyperinsulinemic response compared to a foregut surgery like a gastric bypass. Surgeries that modulate the hindgut have more potential to disrupt the absorption of vitamins and minerals than foregut surgeries. To prevent this, the transit bipartition technique has been developed in recent years. As a result, various methods have been used in metabolic surgery. The choice of a surgical technique should be specific to the patient.