In general, an operation to lose weight is always the last option. Patients who undergo stomach reduction surgery generally suffer from obesity. Obesity is defined as a BMI of 40 or more. Furthermore, people with a BMI of 35 suffer from obesity if they suffer from serious health problems. The obesity must be proven for at least three years. In addition, other alternatives for weight reduction (changes in diet and lifestyle, medication) should be unsuccessful. Furthermore, a gastric sleeve surgery requires a minimum age of 18 years and a maximum age of 65 years. Mental illnesses, alcohol and drug abuse must be ruled out before any operation. Your specialists from Turkey also recommend a previous multimodal therapy program. This includes six to twelve months of nutritional advice, intensive exercise training and psychiatric treatment.