Fatty liver: how frequent is it and why?

There is increasing evidence that fatty liver may be the most frequent liver disorder in Western countries. However, the epidemiology of fatty liver is still not fully understood and there is a clear need of better assessing and defining the potential role of the risk factors identified by clinical series in the general population. This article reviews the available data on the epidemiology of fatty liver and addresses some important questions that should be answered in much needed future research.