GPT and fatty liver disease: The Chinese diagnostic criteria employ two major components for the diagnosis of NAFLD: (i) liver imaging study meeting diffuse fatty liver criteria and not explained by any other causes; (ii) individuals with components of metabolic syndrome with continuous elevation of ALT or AST and GGT or both from an unknown cause for more than 6 months; and finally, if abnormal fatty liver imaging or zymogram shows improvement after weight reduction and improvement of insulin resistance occurs, the diagnosis of NAFLD is definite.