BackgroundMost patients undergoing bariatric surgery demonstrate elements of the metabolic syndrome (MetS) and can therefore be diagnosed with metabolically unhealthy obesity (MUO). Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) as hepatic manifestations of the MetS occur in many patients with obesity, but their leverage on postoperative improvement to Metabolic Health (MH), defined as absence of any metabolic comorbidity, remains unclear. ObjectivesAim of this study was to assess the influence of liver health status, operative procedure and sex on postoperative switch from a MUO to a MH phenotype. Secondary objective was weight loss to MH. SettingUniversity Hospital, Germany. MethodsPatients that underwent either Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) at our obesity surgery center were included in this retrospective study. Liver biopsy was taken and evaluated for presence of NAFLD/NASH. For diagnosis of MH, blood pressure and laboratory values referring to the MetS were assessed preoperatively and at 3, 6, 12 and 24 months postoperatively. ResultsOne hundred thirty-three Patients (73% female) with a mean BMI of 52.0 kg/m2 and mean age of 43 years were included in this study. 55.6% underwent RYGB, 44.4% underwent SG. NAFLD was found in 51.1%, NASH in 33.8% patients. All patients were diagnosed MUO at baseline. Postoperatively, 38.3% patients (n=51) switched to a MH condition. Mean time to MH was 321 days and mean excess BMI loss to MH was 63.8%. There were no differences regarding liver health status, operative procedure, or sex. ConclusionsBariatric surgery can resolve MUO independent of liver health status, operative procedure, and sex. However, patients should be closely monitored to ensure sustainable long-term outcomes following the switch to the MH condition.