Clear, referenced gut health guides written by a practising gastroenterology specialist

Gut Explained

Plain-English gut health from a gastroenterology specialist

Fatty liver disease (MASLD): what it means and what helps

Written by Ben Johnson, Advanced Clinical Practitioner, Gastroenterology

Last reviewed Next review due October 2027

Fatty liver disease is now the most common liver condition in the UK. It usually causes no symptoms, and it’s often found by chance on a blood test or scan. The good news is that in its early stages it can be reversed. This guide explains the new name, how doctors check whether there’s any scarring, what your results mean, and the changes with the best evidence.

Key points

  • Fatty liver disease means too much fat has built up in the liver. Its medical name changed in 2023 from NAFLD to MASLD.
  • It’s closely linked to being overweight, type 2 diabetes, high blood pressure and high cholesterol.
  • Most people never develop serious liver damage, but some go on to inflammation and scarring (fibrosis), and a few to cirrhosis.
  • Simple blood tests and a FibroScan show whether there’s scarring, usually without a biopsy.
  • Losing 7 to 10% of your body weight, if you’re overweight, can reduce liver fat and inflammation, and even improve scarring.

What is fatty liver disease?

It’s normal for the liver to contain a little fat. Fatty liver disease means fat makes up too much of it. Over time, fat can trigger inflammation, and inflammation can lead to scarring.[3,6]

The new name: MASLD

In 2023, international liver societies agreed new names. Non-alcoholic fatty liver disease (NAFLD) became metabolic dysfunction-associated steatotic liver disease (MASLD). “Steatotic” simply means fatty. The new name describes what drives the condition, rather than what it isn’t.[1]

  • MASLD: fat in the liver, plus at least one metabolic risk factor such as being overweight, type 2 diabetes or prediabetes, high blood pressure, or abnormal cholesterol or triglycerides.
  • MASH: fatty liver with inflammation (previously NASH).
  • MetALD: fatty liver where both metabolic risk factors and higher alcohol intake play a part.

You may still see the older name, NAFLD, in letters and in NICE guidance. They describe almost exactly the same group of people.[1]

Who gets it?

Fatty liver disease is more likely if you:[3,6]

  • are overweight, especially if you carry weight around your middle
  • have type 2 diabetes or prediabetes
  • have high blood pressure or high cholesterol
  • have polycystic ovary syndrome or an underactive thyroid
  • have obstructive sleep apnoea
  • have a family history of fatty liver or diabetes

It can also affect people of a healthy weight, particularly people of South Asian heritage, who tend to develop metabolic problems at a lower weight.[3]

Stages

  1. Fatty liver (steatosis): fat build-up, without inflammation. Reversible.
  2. Inflammation (MASH): the liver is irritated and inflamed. Still reversible.
  3. Fibrosis: scar tissue starts to form. Early fibrosis can improve.
  4. Cirrhosis: severe, permanent scarring. It can lead to liver failure and increases the risk of liver cancer.

Most people with fatty liver stay at the first stage. The main aim of tests is to find the minority who have significant scarring, because scarring, not fat, is what predicts future liver problems.[3,4]

Fatty liver disease is also a warning sign for your heart. Heart disease and stroke are a more common cause of serious illness in people with MASLD than liver disease, which is why your blood pressure, cholesterol and blood sugar matter so much.[3]

Symptoms

Usually none. Some people notice tiredness or a dull ache under the right ribs. Symptoms such as yellow skin or eyes (jaundice), a swollen tummy or leg swelling usually only appear with advanced disease.[6]

See your GP urgently, or call NHS 111, if you have:

  • yellowing of your skin or the whites of your eyes
  • a swollen tummy or swollen legs
  • confusion or unusual drowsiness
  • vomiting blood, or black, tarry poo

Vomiting blood or passing black poo needs emergency care: call 999 or go to A&E.

Tests

Fatty liver is often first suspected from abnormal liver blood tests or an ultrasound scan. Normal liver blood tests don’t rule it out. The key question is then whether there is scarring.[2,4]

Step 1: a blood test score

Your GP may work out a score called FIB-4 from your routine blood tests and your age. A low score makes significant scarring unlikely, and you can usually be looked after by your GP.[3,4]

Step 2: the ELF test or a FibroScan

If the score isn’t low, a second test is used. NICE recommends the enhanced liver fibrosis (ELF) blood test. A score of 10.51 or above suggests advanced scarring and should lead to a referral to a liver specialist. If it’s below 10.51, NICE suggests repeating it every 3 years.[2] Many areas use a FibroScan instead of, or as well as, the ELF test. It’s a quick, painless scan that measures how stiff the liver is, since stiffness rises with scarring, and gives a score for how much fat it contains.[4]

Liver biopsy

Your doctor will also check for other causes of abnormal liver tests, such as viral hepatitis, too much iron in the body and, occasionally, coeliac disease.[2,4]

A liver biopsy is now rarely needed. It’s used when the other tests disagree or another liver condition is suspected.[3,4]

The number that matters most

I carry out FibroScans, and I also developed our paracentesis service, which drains fluid from the tummy of people with advanced liver disease. Seeing both ends of the spectrum is why I take early fatty liver seriously, and why I’m so encouraging about it.

Many people arrive for a scan worried they have cirrhosis because their letter says “fatty liver”. I explain that the stiffness reading is the one that matters most. A high fat score with a low stiffness score is common, and it means there’s fat in the liver but no significant scarring: exactly the stage where the changes you make now work best.

You don’t need a perfect diet or a gym membership. Steady weight loss, moving more, cutting out sugary drinks and keeping alcohol low all add up, and the liver is very good at repairing itself when it’s given the chance.

Ben JohnsonBen Johnson
Advanced Clinical Practitioner, Gastroenterology

Treatment: what makes a difference

There’s no single tablet that cures fatty liver. The most effective treatment is improving metabolic health.[2,3]

Weight loss

If you’re overweight, losing weight is the most effective treatment.[3]

  • Losing about 5% of your body weight reduces liver fat.
  • Losing 7 to 10% can reduce inflammation.
  • Losing 10% or more can improve scarring.

Aim for slow, steady weight loss, around 0.5 to 1kg (1 to 2 pounds) a week. For someone weighing 95kg (about 15 stone), 7% is around 6.5kg (1 stone). Your GP can refer you to local weight management services, and some people may be offered weight-loss medicines or, for people with a very high BMI, surgery.[3]

Everyday changes

  • Be active: aim for 150 minutes of moderate activity a week, such as brisk walking, plus muscle-strengthening activity on 2 days. Exercise reduces liver fat even if your weight doesn’t change.[2,3]
  • Eat a Mediterranean-style diet: plenty of vegetables, fruit, pulses, wholegrains, fish and olive oil, with fewer processed foods.[3]
  • Cut out sugary drinks, including fruit juice and smoothies.
  • Keep alcohol low, within the UK guideline of 14 units a week spread over 3 or more days. If you have significant scarring, your doctor may advise stopping completely.[2,7]
  • Stop smoking.
  • Keep diabetes, blood pressure and cholesterol well controlled. Statins are safe for most people with fatty liver.[3]

Medicines

Some medicines used for diabetes and weight loss also reduce liver fat, and new treatments for liver inflammation are being studied. For people with advanced scarring, a liver specialist may consider other medicines.[2,3] Avoid herbal supplements marketed for the liver. They aren’t proven, and some can cause liver damage.

Follow-up

If tests show no significant scarring, you’ll usually be managed by your GP, with repeat checks every few years.[2] If there’s advanced scarring, you’ll be referred to a liver specialist for monitoring, and people with cirrhosis are usually offered an ultrasound scan every 6 months to look for early liver cancer. Some are also offered a gastroscopy to check for enlarged veins in the food pipe (varices).[3]

Frequently asked questions

Can fatty liver be reversed?

Yes, in the early stages. Fat and inflammation can clear completely with weight loss and lifestyle changes, and early scarring can improve. Cirrhosis can’t be reversed, but its progression can be slowed.

I don’t drink. How can I have fatty liver?

Fatty liver disease is mostly driven by metabolic health, such as weight, blood sugar and cholesterol, not alcohol. That’s why it was renamed.

Is coffee good for the liver?

Studies suggest coffee may be linked to a lower risk of liver scarring, but it’s not a treatment. Weight, activity and alcohol matter far more.

Will I need a liver biopsy?

Probably not. Blood test scores and FibroScan now answer most questions without a biopsy.

Does fatty liver cause tiredness?

It can, although tiredness is common and has many causes. Treating the things that drive fatty liver, such as weight and blood sugar, often improves energy too.

References

  1. Rinella ME, Lazarus JV, Ratziu V, et al. A multisociety Delphi consensus statement on new fatty liver disease nomenclature. Journal of Hepatology 2023;79:1542–1556.
  2. NICE. Non-alcoholic fatty liver disease (NAFLD): assessment and management (NG49). https://www.nice.org.uk/guidance/ng49
  3. European Association for the Study of the Liver (EASL), European Association for the Study of Diabetes (EASD), European Association for the Study of Obesity (EASO). EASL-EASD-EASO Clinical Practice Guidelines on the management of metabolic dysfunction-associated steatotic liver disease (MASLD). Journal of Hepatology 2024;81:492–542.
  4. 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. Journal of Hepatology 2021;75:659–689. https://pubmed.ncbi.nlm.nih.gov/34166721/
  5. Bradford Teaching Hospitals NHS Foundation Trust. What is MASLD? https://bradfordhospitals.nhs.uk/masld
  6. British Liver Trust. Non-alcohol related fatty liver disease. https://britishlivertrust.org.uk/non-alcohol-related-fatty-liver-disease-2
  7. NHS. Alcohol units. https://www.nhs.uk/live-well/alcohol-advice/calculating-alcohol-units/

Please note: This guide is general information, not personal medical advice. Everyone is different: speak to your GP, pharmacist or specialist team about your own symptoms and treatment. This site is independent. It is not part of, or endorsed by, the NHS or any NHS Hospital Trust.

If you have severe pain, are vomiting blood, or have black, tarry stools, call 999 or go to A&E. For urgent advice, call NHS 111.

More guides

Powered by CookieAdmin