Non-alcoholic fatty liver disease (NAFLD) is a condition of excessive hepatic lipid accumulation in subjects that consume less than 20g ethanol per day, without other known causes as drugs consumption or toxins exposure. In Western countries, the rate of this disease lies about 30% in the general adult population. The process of developing NAFLD can start from simple steatosis to non-alcoholic steatohepatitis (NASH), which eventually can lead to cirrhosis and hepatocellular carcinoma in the absence of alcohol abuse. Liver biopsy is considered the "gold standard" of steatosis, fibrosis and cirrhosis. However, it is rarely performed because it is an invasive procedure and investigators are focusing in the application of non-invasive liver damage scores for diagnosis.