Fatty liver disease (MASLD)

What fatty liver disease is

Metabolic dysfunction-associated steatotic liver disease, or MASLD, is a build-up of fat in the liver linked to the metabolic conditions that often travel together: excess weight, particularly around the abdomen, type 2 diabetes or prediabetes, high blood pressure and abnormal cholesterol. It used to be called non-alcoholic fatty liver disease, or NAFLD, and is sometimes written as MAFLD. The change of name reflects the cause, rather than defining it by what it is not.

Fatty liver is usually found because a routine blood test came back abnormal. What those results mean, and what else can cause them, is covered on the abnormal liver function tests page.

It affects about one in three Australian adults, most of whom have no symptoms. In a minority the fat causes inflammation, and over years the inflammation causes scarring, called fibrosis. Advanced fibrosis can progress to cirrhosis and, less often, to liver cancer.

What actually matters: scarring

Fat in the liver, on its own, is common and reversible. The amount of fat seen on ultrasound says little about the risk to the liver. What predicts the future is fibrosis, so assessment is built around finding out whether there is any and how much.

• FIB-4 is a score calculated from age and routine blood tests. A low score reliably excludes advanced scarring, and many people need nothing further.
• Liver stiffness measurement, known as transient elastography or FibroScan, is a painless scan that takes a few minutes and estimates scarring directly. It is used when FIB-4 is not low or when other factors raise concern.
• Liver biopsy is now rarely needed, mainly when the diagnosis is uncertain.

Other causes of an abnormal liver test or a fatty liver are checked at the same time, including alcohol, viral hepatitis, iron overload, autoimmune liver disease and some medicines.

What makes the most difference

Fatty liver is the liver's share of a wider problem, the metabolic syndrome: extra weight around the waist, blood sugar that is high or heading that way, high blood pressure and abnormal cholesterol. Treating that whole picture is what protects both the liver and the heart.

• Weight loss. Losing 7 to 10 per cent of body weight reduces liver fat and inflammation, and losing 10 per cent or more can improve scarring. Sustained change matters more than speed.
• Medicines for weight and diabetes. GLP-1 based medicines, which patients commonly know as Ozempic, Wegovy or Mounjaro, help many people lose weight and reduce liver fat. In April 2026 the TGA gave provisional approval to one of them, commonly known as Wegovy, for adults with fatty liver inflammation (MASH) and moderate to advanced scarring without cirrhosis. It is not on the PBS for this use.
• Exercise, including building muscle. Aerobic activity and resistance training both reduce liver fat, even before weight changes. Keeping muscle matters, particularly while losing weight.
• Heart health. Heart disease, not liver disease, is the most common cause of death in people with fatty liver. Blood pressure, cholesterol and blood sugar should be treated, and anyone with other risk factors, such as diabetes, smoking or a family history of heart disease, should have a heart check with their GP or a cardiologist.
• Diet and lifestyle. A Mediterranean style of eating, fewer sugary drinks and less processed food, alcohol within the national guidelines (none at all with cirrhosis), no smoking and better sleep.
• A team approach. A dietitian, an exercise physiologist or personal trainer, and your GP all have a part, alongside liver assessment and follow-up.

Where weight is the main driver, medical and endoscopic weight management is part of the same practice.

Follow-up

People without significant scarring are usually followed up by their GP, with the fibrosis assessment repeated every few years. Those with advanced fibrosis or cirrhosis need regular specialist review, including liver cancer surveillance with ultrasound every six months and screening for varices.

Where fatty liver disease is managed in Sydney

A/Prof Viraj Kariyawasam is a consultant gastroenterologist and hepatologist. Fatty liver disease, including assessment of scarring, is managed at consultation in Norwest, Rouse Hill, Pennant Hills and Macquarie Park.

Where further assessment or endoscopy is needed, it is arranged at Norwest Private Hospital, Macquarie University Hospital and Pennant Hills Day Surgery. A referral from your GP is needed for a consultation.