Inclusion Criteria:  Age ≥18 years Patients with a confirmed diagnosis of NAFLD Patients affiliated to French social security Written informed consent signed by the patient  Exclusion Criteria:  Refusal or inability (lack of capacity) to give informed consent. Average alcohol ingestion greater than 21/14 units/week (males/females) in the preceding 6 months or history of sustained excessive consumption of alcohol in past 5 years. History or presence of Type 1 diabetes mellitus. Presence of any other form of chronic liver disease except NAFLD Recent (within 12 months) or concomitant use of agents known to cause hepatic steatosis (long-term systemic corticosteroids [>10 days], amiodarone, methotrexate, tamoxifen, tetracycline, high dose oestrogens, valproic acid). Any contra-indication to liver biopsy. Recent (within 3 months) change in dose/regimen or introduction of Vitamin E (at a dose ≥400 IU/day), betaine, s-adenosyl methionine, ursodeoxycholic acid, silymarin or pentoxifylline. Non-French speaking/unable to access an interpreter. Patients judged by the investigator to be unsuitable for inclusion in the study (e.g. judged by the physician as unlikely to be compliant with the study protocol). Pregnant or breastfeeding women Patient under legal protection measure (tutorship or curatorship) and patient deprived of freedom