Non-alcoholic fatty liver disease (NAFLD) is the buildup of fat in the liver that is not caused by drinking too much alcohol. People who have it do not have a history of heavy drinking. NAFLD is closely related to being overweight. Nonalcoholic Steatohepatitis (NASH) is a form of nonalcoholic fatty liver disease (NAFLD) in which you have hepatitis—inflammation of the liver—and liver cell ....