Thanks for your query. Enlarged liver can be due to fat deposition in it (fatty liver). It is an indication for insult to liver. The function of liver can be assessed by doing blood test called liver function tests. To know the size of liver you need to get an ultrasound scan or CT scan. The restoration of liver function or liver size depends on the cause of liver damage. It is very difficult to reverse the damage of liver, we can only prevent further damage. You need to avoid oily, spicy foods. Do not use any medications with out contacting the doctor which ca be damage to the liver. Avoid alcohol which is the common cause of liver damage. There are certain liver protective medicines the doctors prescribe but their credibility is controversial.