Evaluation of the Physiological Stability Variability and Robustness of NIS4

Inclusion Criteria: * Histologically documented steatohepatitis (NASH) with at least minimal (grade 1) hepatocyte ballooning and inflammation on a biopsy performed in the past year. * OR, if a biopsy is not available: 1. Presence of metabolic risk factors (see below) AND 2. Documentation of steatosis on imaging (hepatic ultrasound, CT scan or MRI) AND 3. Increased ALT \>30 IU/L OR liver stiffness \>5 kPa on Fibroscan * Metabolically stable condition, in particular no weight change \>5% in the past 6 months, anticipated stable diabetic therapy during the study period * No other identifiable cause of liver disease * Patients affiliated to French social security. * Written informed consent signed by the patient Exclusion Criteria: * Patient with Hepatitis B or C. * Presence of any other form of chronic liver disease * Average alcohol consumption greater than 20 g/day for females and 30 g/day for males in the preceding 6 months or history of sustained excessive consumption of alcohol in past 5 years. * Severely uncontrolled diabetes (HbA1c\>9.5%) * 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). * 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. * HIV infection. * Person not fasted 12 hours (T10, T12, D0). * Substantial diet modification in the 4 months prior to inclusion. * 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. * Patient is a participating in another research study