Effect of an Early Time Restricted Eating Mediterranean Diet Compared to Naltrexone/Bupropion on Liver Fibrosis in People With Cardiometabolic Risk Factors in a Hospital Outpatient Clinic (MEDFAST-study)

In the Netherlands, there are many people with cardiometabolic diseases. More than half of these people also have fatty liver. This is a build-up of fat in the liver (steatosis) and can lead to long-term scarring (fibrosis) and even death of the liver. Losing weight can help reduce this. Losing weight can be done with medication such as naltrexone/bupropion, which is often prescribed to people with cardiometabolic diseases, but losing weight can also be done with diet. In this study, the investigators want to combine a Mediterranean diet (with lots of vegetables, fruits, whole grain products, nuts and olive oil) with intermittent fasting. In addition participants are not allowed to eat after the evening meal. The investigators will compare this with a group of participants receiving naltrexone/bupropion, to see if a diet with intermittent fasting might be better for reducing liver steatosis and fibrosis in people with cardiometabolic diseases.

Inclusion Criteria: * BMI \> 30 kg/m2 or BMI \> 27 kg/m2 and at least one cardiometabolic risk factor (T2D, hypertension, dyslipidaemia) * Moderate to severe liver fibrosis, measured as liver stiffness by transient elastography (LSM \> 7.0 kPa and \< 13.6 kPa) * Aged 18-75 years * Written informed consent Exclusion Criteria: * An insufficient comprehension of the Dutch language (spoken and written) * Female who is pregnant, breast-feeding or intends to become pregnant * Participants with an established diagnosis of liver pathology like, but not limited to: Hepatitis B, Hepatitis C, Autoimmune hepatitis, Wilson's disease, Hemochromatosis, Primary biliary cholangitis, Primary sclerosing cholangitis, Alcoholic liver disease * History of liver transplant, or current placement on a liver transplant list * History of cirrhosis and/or hepatic decompensation, including ascites, hepatic encephalopathy or variceal bleeding * Participants with active HIV infection and/or treatment * Participants with diagnosed malignancies with or without active treatment * Participants with history or pre-existing renal disease (eGFR \<30 mL/min/1.73 m2) * Participants with corticosteroid induced diabetes (while still using corticosteroids) * Participants using GLP-1 agonists for less than 3 months or not yet on a stable dose * Participants using MAO-inhibitors, opioids and/or methadone (due to contraindication) * Known or suspected excessive alcohol consumption (\>30 grams/day for males or \>20 grams/day for females. One drink is equivalent to 10 grams of alcohol) * Previous or planned (during the trial period) obesity treatment with surgery. However, previous interventions that, due to reversal or removal, do not have any influence on the patient's weight, in the opinion of the investigator, are allowed. * Participants with a history or evidence of any other clinically significant condition or planned or expected procedure that in the opinion of the investigator, may compromise the patient's safety or ability to complete the study