The most common cause of fatty liver enlargement is being overweight/obese and alcohol consumption. Fatty liver in initially stages is reversible, but if one does not take measures such as control of diet/weight loss and avoidance of alcohol, it can progress to more severed forms called steato-hepatitus and even cirrhosis which is irreversible.

[ ] Fatty liver can be due to alcohol intake or due to obesity ,can be due non Alcoholic fatty liver disease (NAFLD).Generally these are reversible if care taken means need to do physical exercise , need to decrease weight. Quit alcohol if being consumed. There are some medicines which boost up liver and helps in regaining function of liver , advised when required. Feel free to ask any further quary related to this.