Fatty Liver (MASLD): Symptoms, Causes, Diet and Can It Be Reversed?
Medically reviewed by Sabeen Munib M.D.Fatty liver means extra fat has built up inside the liver, and most people who have it feel completely fine. The common type is now called MASLD (metabolic dysfunction-associated steatotic liver disease), the new name for what used to be called NAFLD, and it is closely tied to insulin resistance, type 2 diabetes, extra weight and high triglycerides. It is usually found on a blood test or an ultrasound, and for many people it can improve, and even reverse, with weight loss, more activity and less alcohol.
What is fatty liver?
A healthy liver holds only a small amount of fat. When fat makes up a larger share of the liver, doctors call it fatty liver, or hepatic steatosis. It is one of the most common liver conditions in the United States and affects roughly a quarter of adults, many of whom do not know they have it.
For most people, fat in the liver stays just that: fat, with no lasting damage. In some people, the fat leads to inflammation and liver cell injury. Over years, that inflammation can cause scarring (fibrosis), and in a smaller group the scarring can progress to cirrhosis. The goal of finding fatty liver early is to spot the people at risk of scarring and to act before it advances.
What is the difference between MASLD and NAFLD?
They describe largely the same condition. In 2023, liver specialist groups renamed it so the name says what causes it rather than what does not. You may still see the old names on older lab reports or websites.
- NAFLD (nonalcoholic fatty liver disease) is now MASLD: metabolic dysfunction-associated steatotic liver disease
- NASH (nonalcoholic steatohepatitis), the inflamed form, is now MASH: metabolic dysfunction-associated steatohepatitis
- Steatotic liver disease (SLD) is the umbrella term for any fatty liver
- MetALD is the term for people who have MASLD and also drink more than a moderate amount of alcohol
To be called MASLD, a person has fat in the liver plus at least one metabolic risk factor, such as extra weight or a large waist, raised blood sugar or diabetes, high blood pressure, high triglycerides or low HDL (good) cholesterol.
Who gets fatty liver?
MASLD grows out of the same metabolic problems that lead to type 2 diabetes and heart disease. The risk is higher if you have:
- Insulin resistance or prediabetes
- Type 2 diabetes
- Overweight or obesity, especially fat around the belly
- High triglycerides or low HDL cholesterol
- High blood pressure
- PCOS or sleep apnea
It can also happen at a normal weight. Asian Americans, including many South Asian and East Asian patients we see in Irvine, can develop metabolic problems and fatty liver at a lower body weight. Hispanic Americans also have higher rates. Children and teens can have it too.
Read more about the signs of insulin resistance, the most common root cause
What are the symptoms of fatty liver?
Usually there are none. Most people find out by chance, from a routine blood test or an ultrasound done for another reason. When symptoms do appear, they are vague:
- Feeling tired
- A dull ache or fullness in the upper right side of the belly
Clear symptoms usually mean the liver is already badly scarred. Signs of advanced liver disease include:
- Yellow skin or eyes (jaundice)
- Swelling in the belly or legs
- Easy bruising or bleeding
- Itchy skin
- Confusion or unusual sleepiness
- Vomiting blood or black, tarry stools
Because fatty liver is silent until late, waiting for symptoms is not a good plan. Testing is how you find it.
How is fatty liver diagnosed?
Doctors usually put together a few simple pieces. Most people never need a liver biopsy.
- Liver enzymes (ALT and AST) on a routine blood panel. These may be raised, but many people with fatty liver have normal enzymes, so a normal result does not rule it out.
- An ultrasound, CT or MRI that shows fat in the liver. Ultrasound is the most common first picture.
- Blood tests to rule out other causes, such as hepatitis B and C, iron overload, some medicines and alcohol.
- A FIB-4 score, a free calculation from your age, AST, ALT and platelet count that estimates the chance of liver scarring.
What does a FIB-4 score mean?
- Below 1.3: low risk of advanced scarring. Recheck every one to three years, depending on your other risk factors.
- 1.3 or higher: the next step is usually a stiffness test of the liver.
The stiffness test is called elastography. The most common type, often known as FibroScan, is a quick, painless ultrasound-style scan that measures how stiff the liver is. A stiffer liver means more scarring. Results in the low range are reassuring, while higher results usually lead to a referral to a liver specialist.
Who should be checked for fatty liver?
- Adults with type 2 diabetes or prediabetes, even if their liver enzymes are normal
- Adults with obesity plus another metabolic risk factor
- Anyone with raised liver enzymes or fat seen on imaging
Can fatty liver be reversed?
For many people, yes. Fat in the liver responds to weight loss and lifestyle change, and inflammation and early scarring can improve too. Even a modest weight loss lowers liver fat, and more weight loss tends to bring more benefit to the liver. Losing weight gradually is safer than crash dieting.
The changes that help the liver most:
- Lose weight steadily if you carry extra, through eating less and moving more
- Aim for at least 150 minutes a week of moderate activity such as brisk walking, plus some strength work
- Cut back on alcohol, or stop it completely if you have any liver scarring
- Treat the conditions that feed fatty liver: blood sugar, blood pressure, cholesterol and sleep apnea
Advanced scarring and cirrhosis are harder to undo, which is why finding fatty liver early matters.
What is the best diet for fatty liver?
There is no single special liver diet. A Mediterranean-style pattern is the one most often recommended, and the main goal is fewer calories overall if you need to lose weight.
- Eat more vegetables, fruit, beans, lentils, whole grains, nuts, olive oil and fish
- Cut sugary drinks, juice and sweets, since added sugar, especially fructose, adds to liver fat
- Limit white bread, white rice, pastries and other refined carbs
- Limit red and processed meats and fried foods
- Be careful with supplements and herbal products, since some can harm the liver; ask before starting one
Does alcohol make fatty liver worse?
Yes. Alcohol and metabolic fatty liver add to each other. Heavy drinking on its own causes alcohol-related liver disease, and people with MASLD who also drink more than a moderate amount are now labeled MetALD.
- If you have fatty liver with no scarring, drink less, and talk with your doctor about how much is safe for you
- If you have significant scarring or cirrhosis, the advice is not to drink at all
Are there medicines for fatty liver?
For most people with simple fatty liver, the treatment is lifestyle change plus good control of blood sugar, blood pressure and cholesterol. Medicines come in for people with the inflamed form and scarring.
- Rezdiffra (resmetirom) is FDA-approved, along with diet and exercise, for adults with MASH and moderate to advanced liver scarring who do not have cirrhosis. It is started and followed by liver specialists.
- Wegovy is FDA-approved for chronic weight management and also, along with diet and exercise, for adults with MASH and moderate to advanced scarring who do not have cirrhosis. Whether it fits depends on how your liver disease is staged.
- For people with type 2 diabetes or obesity, some diabetes and weight medicines may also help the liver as part of the overall plan.
When should you see a liver specialist?
Most people with fatty liver are cared for by their primary care doctor. A referral to a hepatologist (liver specialist) is usually needed if:
- Elastography or other tests show moderate or advanced scarring
- Results are unclear and the stage of the disease needs to be pinned down
- There are signs of cirrhosis, or a medicine such as Rezdiffra is being considered
- Another liver disease may also be present
Go to urgent care or the emergency room for yellow skin or eyes with fever, confusion, vomiting blood, black stools or a quickly swelling belly.
How Dr. Munib approaches fatty liver
Dr. Munib starts with your history: weight changes, blood sugar, family history of diabetes or liver disease, alcohol, sleep, medicines and supplements. The exam includes blood pressure, waist size and a check for signs of insulin resistance.
Labs may include liver enzymes, a platelet count to calculate FIB-4, an A1C, a cholesterol panel and tests for other liver causes. Depending on the results, she may order an ultrasound or elastography, or refer you to a liver specialist. For most patients, the plan centers on steady weight loss and treating blood sugar, cholesterol and blood pressure. For adults who qualify, she may discuss a brand-name weight medicine as one option.
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If you have been told you have a fatty liver, or you have diabetes, prediabetes or extra weight and have never been checked, a visit and simple blood work are the place to start. The Pur Health is in-network with most PPO plans, and cash visits are $190 for new patients and $150 for returning patients. Visit our Irvine office at 114 Pacifica, Suite 280, or call (949) 647-5234.