Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome and is defined by the accumulation of fat in > 5% of hepatocytes at the histological level or by proton magnetic resonance spectroscopy (1H-MRS) in association with insulin resistance in patients who are not alcohol consumers (< 20–30 g/day or < 21 standard drinks/week for men and < 10–20 g/day or < 14 standard drinks/week for women) [1,2]. This disease, largely unknown few decades ago, affects almost a quarter of adults worldwide ranging from 13.5% in Africa to approximately one third in the Middle East and South America [1–3] and therefore, it is now considered the commonest chronic liver disease.
