The sleeve gastrectomy or sleeve gastrectomy is a surgical operation. This operation is performed without a large incision, but with four approx. 1 cm incisions. A part of the stomach is removed (approx. 80% percent) and the remaining part (approx. 20%) remains as the new, smaller stomach. In the distant part of the stomach, hunger hormones (ghrelin) are produced. After the operation, patients feel less hungry and the new small stomach means that they are full more quickly and eat less food. The weight loss after the operation is approx. 60-70% of the excess weight and obesity concomitant diseases, such as type 2 diabetes, sleep apnea, hypertension and others, disappear or improve sustainably. Operation time: approx. 30 minutes