The damage that occurs is similar to that caused by drinking too much alcohol, but fatty liver disease affects people who drink little or no alcohol. At its most severe, the condition can progress to cirrhosis and liver failure. Around 20% of people with non-alcoholic fatty liver disease develop cirrhosis.
Fatty liver is characterised by liver inflammation, which may results in scarring and irreversible damage. The condition is increasingly common in the Western world and is now the number one form of chronic liver disease in the United States.
It mostly affects people in their 40s and 50s who are also at risk of heart disease due to obesity and type 2 diabetes. It is linked to metabolic syndrome, which is a range of abnormalities including increased abdominal fat and poor insulin use.