Published online Sep 28, 2017. doi: 10.3748/wjg.v23.i36.6571
Peer-review started: July 15, 2017
First decision: August 10, 2017
Revised: August 21, 2017
Accepted: September 5, 2017
Article in press: September 5, 2017
Published online: September 28, 2017
Core tip: Nonalcoholic fatty liver disease (NAFLD) is a pandemic disease. Recent evidence highlights new concepts in clinical and pathogenic heterogeneity of NAFLD, a systemic disorder with a multifactorial pathogenesis and protean clinical manifestations. Other than the classical obese phenotype of NAFLD, a lean though metabolically abnormal variant has been recognized. Simple steatosis is no more considered a benign condition; insulin resistance is necessary but not sufficient for the disease progression, and NAFLD is not only a mere hepatic manifestation of metabolic syndrome, but may forerun the development of metabolic syndrome and cardio-renal complications. Several non-invasive diagnostic tests are now available and new drug treatment options are coming.