Key points
- Fatty liver is very common and in most people it does not progress. What determines the outlook is not the fat but the fibrosis (scarring).4
- Ultrasound shows fat but not fibrosis. And normal liver enzymes do not rule it out.
- Assessment starts with a score calculated from routine blood tests (FIB-4) and, if it is not low, with elastography (FibroScan), which avoids a biopsy in most people.2,3
- Sustained weight loss is the most effective treatment: 7-10% improves inflammation and 10% or more can reverse fibrosis.5
- Since 2023 the condition has been called MASLD: metabolic dysfunction-associated steatotic liver disease.1
This article summarises the evidence and clinical guidelines so you can understand your situation. It does not replace an individual assessment.
“You have fatty liver, but don’t worry.” It is probably the sentence most often heard after an abdominal ultrasound, and it leaves patients in limbo: they know they have something, they don’t know how much it matters and nobody has told them what to do.
The sentence is not entirely wrong. Most fatty livers do not progress. The problem is that some do, and a standard ultrasound cannot tell you which group you belong to. This article explains what the finding means, how to find out whether it matters in your case and which treatments have been shown to work.
What fatty liver is and why it has a new name
We speak of fatty liver when more than 5% of liver cells contain fat. For decades it was called “non-alcoholic fatty liver disease”, a name that defined the condition by what it was not. In 2023 the main hepatology societies agreed to call it metabolic dysfunction-associated steatotic liver disease (MASLD), because its cause is almost always metabolic: excess weight, insulin resistance, diabetes, high blood pressure or abnormal cholesterol and triglycerides.1
The new system also recognises a mixed category, MetALD, for people who have both metabolic risk factors and significant alcohol intake. In practice, the two causes add up.1
When the fat is accompanied by inflammation and cell damage, it is called steatohepatitis (MASH). It is this inflammation, sustained over years, that gradually leaves scarring.
Fat is not the same as fibrosis
Two things that are constantly confused need to be kept apart:
- Fat is what the ultrasound sees and what gives the finding its name. On its own it says little about the liver’s future.
- Fibrosis is the scarring left by sustained inflammation. It determines the outlook, and it cannot be seen on a standard ultrasound.
A study that followed 619 patients with a liver biopsy for a median of almost 13 years found that, of all the microscopic findings, only the stage of fibrosis was associated with overall mortality, transplantation and liver complications. Neither the amount of fat nor the degree of inflammation predicted outcomes on their own.4
Two people, the same report, opposite outlooks
Two patients can have exactly the same “fatty liver” written on their ultrasound report and completely different futures. What separates them is how much fibrosis they have, and that does not appear on the report.
Why normal blood tests are less reassuring than they seem
This is the point that surprises people most: you can have advanced fibrosis with normal liver enzymes. Liver enzymes (AST and ALT) reflect active damage to liver cells at a given moment, not accumulated scarring. A liver that has been slowly inflamed for years can produce perfect numbers.
That is why guidelines no longer use liver enzymes to decide who is at risk. Instead they recommend starting with FIB-4, a score calculated from age, liver enzymes and platelet count, all part of a routine blood test.2,3
| FIB-4 | What it means | Next step |
|---|---|---|
| Below 1.3 | Low risk of advanced fibrosis | Manage metabolic risk factors and reassess periodically |
| 1.3 to 2.67 | Indeterminate result | Elastography (FibroScan) |
| Above 2.67 | High risk of advanced fibrosis | Elastography and review by a liver specialist |
What FibroScan is and what it adds
FibroScan is a form of transient elastography: an ultrasound technique that measures how stiff the liver is. The logic is simple: the more scarring a tissue has, the stiffer it is and the faster a wave travels through it. The result is expressed in kilopascals (kPa).
The same examination quantifies the amount of fat (the CAP parameter), which is far more informative than the “bright liver” described on an ultrasound report.
- It is painless, with no needles or contrast
- No sedation is needed
- It takes a few minutes
- You only need to fast for a few hours
- The result is available immediately
| Liver stiffness | Interpretation | What it usually means |
|---|---|---|
| Below 8 kPa | Advanced fibrosis very unlikely | Follow-up and metabolic control |
| 8 to 12 kPa | Grey zone | Interpret together with blood tests; sometimes further tests |
| 12 kPa or more | Advanced fibrosis likely | Specialist follow-up; check for cirrhosis and its complications |
Its great advantage is that, in most cases, it avoids a liver biopsy, which until not so long ago was the only way to know the stage of fibrosis.2,3
Who should be assessed
European guidelines recommend actively looking for fibrosis in people at higher risk, even if they feel well:2
- Type 2 diabetes
- Obesity, especially with other metabolic risk factors
- Persistently raised liver enzymes
- Fatty liver seen on any imaging test, even if you were told it was not important
- High blood pressure, cholesterol or triglycerides
- Unexplained raised ferritin
- A family history of cirrhosis
- Alcohol intake that, on top of the above, may be contributing
What actually works
There is no pill that cures fatty liver on its own, and anyone who promises one should be treated with caution. What does exist is a set of measures with proven benefit.
The most powerful is sustained weight loss. In a study with biopsies before and after a year of lifestyle change, weight loss was associated with stepwise improvement in the liver:5
- A Mediterranean-style diet, paying particular attention to sugary drinks, added fructose and ultra-processed foods.2
- Regular exercise, which benefits the liver even when weight barely changes.2
- Control of diabetes, cholesterol and blood pressure, together with your GP.
- Keeping alcohol to a minimum, and stopping it altogether if there is advanced fibrosis.2
- Reviewing medicines and supplements: some products sold “for the liver” can harm it.
In recent years drugs with a direct effect have appeared. In a phase 3 trial of patients with steatohepatitis and moderate or advanced fibrosis, semaglutide (a GLP-1 analogue) resolved steatohepatitis in 63% of patients compared with 34% on placebo, and improved fibrosis in 37% compared with 22%.6 It is not a shortcut or a consumer product: it requires a specific medical indication, follow-up and the support of lifestyle changes.
Common myths
“If my liver enzymes are normal, my liver is fine.”
Advanced fibrosis can occur with normal liver enzymes. That is why guidelines recommend FIB-4 and elastography, not liver enzymes, to assess risk.2,3
“Fatty liver is caused by drinking.”
The commonest cause is metabolic: excess weight, insulin resistance or diabetes. Alcohol adds to it, but is not necessary to have it.1
“Only overweight people get it.”
It also occurs in people of normal weight who have insulin resistance, diabetes or abnormal blood lipids.
“There are “detox” products that cleanse the liver.”
No supplement has been shown to treat fatty liver, and some herbal products are a known cause of liver damage.
“If it doesn’t hurt, nothing is wrong.”
Fatty liver causes no symptoms until very advanced stages. The only way to know is to measure it.
“You need a biopsy to know the degree of fibrosis.”
Combining FIB-4 and elastography correctly classifies most patients without a biopsy.3
Warning signs: do not wait
See a doctor promptly if you also have…
Fatty liver is not an emergency, but these signs suggest there may be advanced liver disease:
- Yellowing of the skin or eyes
- A swollen abdomen from fluid build-up, or swollen legs
- Vomiting blood or black stools (in that case, go to A&E)
- Confusion, drowsiness or changes in behaviour
- A low platelet count on blood tests without another explanation
- A FibroScan of 12 kPa or more, or a FIB-4 above 2.67
How I approach it in clinic
At the first visit I review your history, previous blood tests and metabolic risk factors, and calculate your FIB-4. I perform the ultrasound and FibroScan in the same appointment, so you leave knowing how much fat and how much stiffness your liver has, and what that means for you.
With that baseline, the plan stops being generic advice: we set specific goals and repeat the elastography after a period, usually between one and three years depending on risk, to check whether fibrosis is stable, improving or progressing.2 Without that measurement, you are left with the subjective feeling that you are doing the right things, which does not always match what is happening to the liver.
Have you been told you have fatty liver and nobody has explained what it means?
Ultrasound and FibroScan in a single visit, with a clear plan and a measurable starting point.
Frequently asked questions
Can fatty liver be cured?
Fat and inflammation are reversible, and early fibrosis can also regress. The measure that achieves this most often is sustained weight loss of 7-10% or more.5
What is the best diet for fatty liver?
The best supported is the Mediterranean pattern, cutting down on sugary drinks, ultra-processed foods and alcohol. More than any specific diet, what matters is that the change is sustained.2
Can I drink alcohol if I have fatty liver?
It is wise to keep it to a minimum. If there is already advanced fibrosis, the recommendation is not to drink.2
Do Ozempic, Wegovy or similar drugs help?
Semaglutide has been shown to improve steatohepatitis and fibrosis in a phase 3 trial.6 Its use should be decided by a doctor case by case and combined with lifestyle changes.
How often should FibroScan be repeated?
It depends on the result and on risk factors. It is usually repeated after one to three years; sooner if there is significant fibrosis or a major change in weight.2
References
- Rinella ME, et al. A multisociety Delphi consensus statement on new fatty liver disease nomenclature. J Hepatol. 2023 (published simultaneously in Hepatology and Ann Hepatol). PubMed
- European Association for the Study of the Liver (EASL), EASD, EASO. EASL–EASD–EASO Clinical Practice Guidelines on the management of metabolic dysfunction-associated steatotic liver disease (MASLD). J Hepatol. 2024. Full text
- European Association for the Study of the Liver. EASL Clinical Practice Guidelines on non-invasive tests for evaluation of liver disease severity and prognosis – 2021 update. J Hepatol. 2021. PubMed
- Angulo P, et al. Liver fibrosis, but no other histologic features, is associated with long-term outcomes of patients with nonalcoholic fatty liver disease. Gastroenterology. 2015. PubMed
- Vilar-Gomez E, et al. Weight loss through lifestyle modification significantly reduces features of nonalcoholic steatohepatitis. Gastroenterology. 2015. PubMed
- Sanyal AJ, et al. Phase 3 trial of semaglutide in metabolic dysfunction–associated steatohepatitis. N Engl J Med. 2025. NEJM
Links go to PubMed or the original publication and open in a new tab.
Related reading
Dr Fernando Casals Seoane
Consultant gastroenterologist with a PhD in Medicine from the Autonomous University of Madrid. He has worked at La Princesa University Hospital since 2009 and sees private patients at Ruber Juan Bravo Hospital. Certified by the European Board of Gastroenterology and Hepatology and honorary lecturer at the UAM. Principal investigator in international clinical trials on acute pancreatitis, including WATERFALL (NEJM, 2022).
Transparency: this article is not sponsored and does not promote any product or brand. All sources are linked.