Investigators include 20 patients qualified for the bariatric procedure with BMI > 40 kg/m2 or a BMI > 35kg/m2 with the presence of comorbidities. The average body weight in the group was 143.85kg with an average BMI of 49.16kg/m2. Before the procedure, investigators evaluated the severity of the non-alcoholic fatty liver disease in each patient using the Sherif Saadeh ultrasound scale. Investigators also evaluated the levels of the liver enzymes. Follow up was performed twelve months after surgery.