just to clarify the delay in docT's reply, the major causes of fatty liver disease are: obesity; excessive alcohol, diabetes, malnutrition, high lipid levels in the bloodstream, inborn metabolic disorders of glycogen, galactose, tyrosine, or homocysteine, as a side-effect of some drugs and with various illnesses causing a fever, and in some cases crash dieting.
Fasting will generally rejuvenate and cleanse the Liver if prolonged, and where for example after my own two prolonged fasts I still have very "normal" liver-function after numerous blood-tests in 2006, with no evidence of or symptoms of a fatty liver.
I think it is potentially alarmist and erroneous to believe otherwise, whatever docT has already stated.