NAFLD Study: US vs Liver Biopsy

Inclusion Criteria: 1. Patients who are candidates for bariatric surgery between the ages of 18 and 65, * BMI\> 40 kg / m2, in the absence of any other comorbidity * BMI\> 35 kg / m2, in the presence of comorbidities among those classically considered to be associated with obesity * ICM\> 30 kg / m2, in the presence of T2DM not in glycometabolic compensation 2. Patients who are candidates for laparoscopic cholecystectomy for symptomatic calculi with BMI\> 30 Exclusion Criteria: * Age ≤ 18 or ≥ 65 * Any concurrent surgical procedure except cholecystectomy and hiatal hernia repair * Conversion into laparotomy surgery * Post-operative complications requiring new surgical treatment * Patient not compliant in the follow-up