Metabolic Dysfunction-Associated Steatotic Liver Disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a type of steatosis that’s caused by factors other than excessive alcohol use. The exact cause isn’t completely understood, but it often occurs with other metabolic disorders such as high cholesterol, obesity and diabetes.

Overview

A healthy liver and a fatty liver.
Metabolic factors such as body mass and blood sugar can cause a fatty liver.

What is metabolic dysfunction-associated steatotic liver disease (MASLD)?

Steatotic (fatty) liver disease (SLD) occurs when your body begins storing fat in your liver. Some fat in your liver is normal, but when more than 10% of your liver’s weight is fat, it may begin to suffer. Excessive alcohol use is one common reason for SLD. But many people develop it without using alcohol. This is called metabolic dysfunction-associated steatotic liver disease (MASLD).

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How common is this condition?

MASLD affects up to 25% of people worldwide. Most people won’t have symptoms, and some may never know they have the condition. But 2% to 5% of people will experience complications from the fat in their livers. When fat leads to inflammation and cell damage in your liver, it’s called steatohepatitis. The non-alcohol related version is called metabolic dysfunction-associated steatohepatitis (MASH).

Previously, MASH was known as non-alcohol related steatohepatitis (NASH).

Who does MASLD affect?

It can affect anyone, including all ages and races. But it’s more common in people of Hispanic descent and less common in Black people. Middle age, weight and diabetes are also commonly associated with MASLD. For example, up to 75% of people who have obesity or diabetes, and up to 90% of people who have advanced or class III obesity, have MASLD.

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Symptoms and Causes

What are the symptoms of metabolic dysfunction-associated steatotic liver disease (MASLD)?

People typically don’t experience symptoms until MASLD progresses to MASH (metabolic dysfunction-associated steatohepatitis). With MASH, you may begin to have symptoms of inflammation, such as pain and swelling in your upper right abdomen, where your liver is. But you may not notice symptoms until MASH has progressed to more severe liver damage. MASLD merely lays the groundwork.

What causes a fatty liver in a non-drinker?

The answer to this is not yet entirely clear. But researchers suspect several factors at work, including:

  • Metabolic syndrome. MASLD seems to be linked to a group of related metabolic disorders involving high BMI (body mass index), high blood lipid levels, high blood pressure and diabetes. These factors seem to influence each other and lead to collective changes in how your body metabolizes nutrients and stores fats.
  • Diet and nutritional causes. Researchers have also found that a diet high in fructose may increase your risk of developing MASLD. Fructose is one of the ingredients in common table sugar and is the dominant ingredient in high fructose corn syrup, a common sweetener. It’s highly linked to metabolic syndrome.
  • Genetics. Certain genes may make you more likely to develop MASLD. This may help explain why some people get it without any of the other common risk factors. It may also help explain why people of certain races seem to get it more often.
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What are the possible complications of metabolic dysfunction-associated steatotic liver disease (MASLD)?

  • Steatohepatitis. Up to 20% of people with MASLD may develop metabolic dysfunction-associated steatohepatitis (MASH), a state of chronic liver inflammation. This can do progressive damage to your liver, eventually resulting in scarring of the tissues (cirrhosis).
  • Pregnancy complications. MASLD in pregnancy is associated with an increased risk of complications for both the pregnant person and the fetus. In particular, pregnant people are three to four times more likely to experience hypertensive complications like preeclampsia.

Diagnosis and Tests

How is metabolic dysfunction-associated steatotic liver disease (MASLD) diagnosed?

Your healthcare provider may suspect MASLD during a routine checkup if your blood panel shows high levels of certain liver enzymes or your liver appears enlarged on an imaging test. They may recommend further blood tests to rule out other causes of elevated liver enzymes. They may also want to try a more sensitive imaging test, such as a CT scan (computed tomography scan) or MRI (magnetic resonance imaging), to get a better look at your liver.

Another way of diagnosing MASLD is to take a liver biopsy. That means collecting a sample of your liver tissue to test in the lab. Your healthcare provider collects the sample by inserting a needle into your liver. By analyzing the tissue, they can tell how much fat it has and whether there’s any evidence of steatohepatitis (MASH) or permanent scarring (cirrhosis).

Management and Treatment

Is metabolic dysfunction-associated steatotic liver disease reversible?

While there’s no medicine yet to reverse steatotic (fatty) liver disease, making changes to what you eat, how much you drink and increasing your activity levels can help. Many people find that they can slow, stop and even reverse the fat accumulation in their liver by managing metabolic factors such as weight, cholesterol (and other blood lipids), blood pressure and blood sugar. However, once MASH progresses to cirrhosis of your liver, the damage becomes more permanent.

The FDA (U.S. Food and Drug Administration) approved the drug resmetirom (Rezdiffra™) for the treatment of MASH in March 2024. Healthcare providers recommend using this medication in combination with nutritional changes and increased physical activity. Your provider can let you know if resmetirom is right for your situation.

How long does it take to reverse a fatty liver?

Healthcare providers recommend losing at least 3% to 5% of your body weight to begin to see results in your liver. (Current research suggests that even 1% weight loss may improve outcomes.) They also recommend that you aim to lose no more than 1 to 2 pounds per week. Rapid weight loss can make MASLD worse. Take your time with a conservative diet and exercise program. Aim for 30 minutes of exercise a day.

Prevention

How can I reduce my risk of developing metabolic dysfunction-associated steatotic liver disease?

Not all risk factors for MASLD are avoidable, but you can work to manage your weight, cholesterol, blood pressure and blood sugar with diet and medication as necessary. Watch your sugar and saturated fat intake, and make sure to see your healthcare provider for regular checkups.

Outlook / Prognosis

How long can you live with metabolic dysfunction-associated steatotic liver disease?

Metabolic dysfunction-associated steatotic liver disease isn’t life-threatening by itself. You may live the rest of your life without having any complications from it. It becomes more complicated for a small percentage of people when it turns to steatohepatitis (MASH), and especially when MASH progresses to cirrhosis. Research suggests that MASLD overall may lower life expectancy by four years.

Living With

What kind of diet is recommended for metabolic dysfunction-associated steatotic liver disease?

Healthcare providers recommend a diet low in saturated fats and rich in unsaturated fats, (especially omega-3s), which help balance cholesterol, blood sugar and blood pressure. The Mediterranean diet is a good example. They also suggest avoiding sugar and keeping your glycemic index low. Replace sweets, processed foods and white bread products with whole fruits, vegetables and grains.

A note from Cleveland Clinic
Metabolic dysfunction-associated steatotic liver disease is increasingly common around the world, especially in Western developed countries where obesity, diabetes and other metabolic disorders are also on the rise. While many factors might be at play, a common factor among these diseases is often an unhealthy diet and a sedentary lifestyle. Fortunately, these things are in our power to change. By doing so, you can reduce the risk and even reverse the course of MASLD.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 02/05/2022.

Learn more about our editorial process.

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