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Important
This article is general information about fatty liver disease, not medical advice or a recommendation, and it does not replace assessment by a qualified professional. Always see an appropriate healthcare professional about your own symptoms, diagnosis and treatment, including before starting, stopping or changing any medication or supplement. The treatment summaries here are for general understanding only and are not prescribing guidance.
Key points
- Fatty liver disease is a build-up of fat in the liver. When this is not due to excess alcohol it is called MASLD (previously NAFLD).
- It is extremely common, usually causes no symptoms, and strongly linked to insulin resistance and poor metabolic health.
- In some people it progresses to inflammation, scarring (fibrosis) and, eventually, cirrhosis.
- It often improves quickly when sugar and overall food intake are reduced and metabolic health is restored. The liver can usually recover well.
- It is both a consequence of poor metabolic health and a driver of further metabolic disturbance.
What it is
Fatty liver disease is the accumulation of excess fat within liver cells. When this occurs, and it is not due to excessive alcohol, it is called metabolic (dysfunction)-associated steatotic liver disease, or MASLD. This name replaced the older term "non-alcoholic fatty liver disease" (NAFLD) in 2023.1 NICE adopted the new names in 2026.2 The new name describes what the disease is (linked to metabolic dysfunction) rather than what it is not (linked to alcohol), and it requires evidence of at least one metabolic risk factor, such as excess weight, raised blood sugar or high blood pressure.1 It exists on a spectrum: simple fatty liver (fat alone), then steatohepatitis (fat plus inflammation, previously NASH, now MASH), then fibrosis (scarring), and finally cirrhosis (advanced, permanent scarring).3
It is one of the most common liver conditions in the world, affecting a large proportion of adults, and it is closely linked to poor metabolic health. It can be thought of as the liver's expression of insulin resistance.
What causes it, and who is at risk
The underlying cause is excessive fat building up in the liver. There are two major drivers for this: the body's safe fat stores are full, and a diet high in sugar and refined carbohydrate. This causes the liver to make fat to try to get rid of the sugar. Fructose, a sugar found in many sweet foods, sugary drinks and fruit juice, is a particular driver of fat build-up in the liver; whole fruit, eaten with its fibre, is less of a concern than fruit juice and refined sugars.3 People who are more obviously at risk include those with excess belly fat, prediabetes or type 2 diabetes, raised blood fat (triglycerides) and high blood pressure. Physical inactivity and stress can both contribute.
Symptoms and signs
Fatty liver usually causes no symptoms and is often found by chance. Advanced liver disease, called cirrhosis, can cause many symptoms such as jaundice, swelling in the abdomen and body, and blood clotting problems.
How it is diagnosed
It is often first suspected from mildly abnormal liver blood tests, though these can be normal even when fat is present.2,3 An ultrasound scan can show fat in the liver. If checking for scarring (fibrosis), the standard approach is to start with a FIB-4 score, worked out from routine blood results and age. If the score is not low, a second test follows: a blood test called ELF (enhanced liver fibrosis), or a painless scan that measures liver stiffness (often called a FibroScan).3 Occasionally a liver biopsy is needed. Assessment of fibrosis is the key step, as it identifies the minority at higher risk.3
The metabolic health perspective
Fatty liver is, in essence, fat in the liver that shouldn’t be there. This is called ectopic fat and is central to insulin resistance. It is both a result of poor metabolic health and a cause of it. This is why fatty liver so often occurs with other conditions such as prediabetes, high blood pressure, type 2 diabetes, and a large waist.
Liver fat responds quickly to change, often faster than fat stored elsewhere in the body. Reducing the sugar, carbohydrate and total fuel (food) intake can lead to significant improvement.
Treatment and management
The aims are to clear liver fat, prevent or reverse inflammation and scarring, and improve the underlying metabolic health. The major focus is lifestyle change, and there are emerging medications for more advanced disease.
Lifestyle and the Health Foundations
This is the main treatment and is highly effective for simple fatty liver.
Nutrition
Reducing sugar, sugary drinks (especially those containing fructose), refined carbohydrate and ultra-processed food directly reduces the fat the liver makes and stores.3 A focus on building meals with plenty of protein and non-starchy vegetables can be helpful, with starchy carbohydrate (bread, rice, pasta, potatoes) reduced, or adjusted to the amount that suits you. Where there is excess weight, losing about 5% of body weight starts to clear liver fat, 7 to 10% improves inflammation, and 10% or more can improve scarring.3 The 28 Day Plan framework may be a useful approach.
Movement
Both aerobic and resistance (strengthening) exercise reduce liver fat, even without much weight change.3,4
Alcohol
Stay within the UK limit of 14 units a week at most; European guidance goes further: it discourages drinking, and says people with advanced scarring or cirrhosis should stop completely, as alcohol adds directly to liver fat and damage.2,3
Sleep and stress
Both support the wider metabolic improvement.
Other non-drug options
- Vitamin E or pioglitazone (a diabetes medicine) may be considered by hospital specialists for adults with advanced scarring. Neither is licensed for this use (off-label), and neither suits everyone.2
- Coffee (without added sugar, caffeinated or not) is associated with lower liver-disease risk in some research studies.3 But the evidence is not strong enough to suggest people should start drinking coffee if they currently do not.
- Correcting vitamin D if low, and being cautious with unnecessary supplements that can stress the liver, is sensible. Discuss any supplement with your pharmacist or clinician.
Medical and pharmaceutical treatments
There is no long-established drug specifically for simple fatty liver, but treatments for the more advanced disease, steatohepatitis (MASH), are now emerging. Resmetirom, a medicine made for MASH, is recommended in European guidance for people with MASH and significant scarring but no cirrhosis, in countries where it is licensed.3 Whether and when such treatments are available on the NHS depends on licensing and NICE. Medicines used for related conditions, particularly the weekly GLP-1 injections used for type 2 diabetes and weight loss (semaglutide, tirzepatide), can reduce liver fat and inflammation. They have not yet been shown to improve scarring, but European guidance says they are safe in fatty liver disease and should be used where someone also has type 2 diabetes or obesity.3 Managing type 2 diabetes, blood pressure and blood fats is part of overall care. If you take a statin, fatty liver is not a reason to stop it.2 People with advanced scarring are followed up by liver specialists.2
Complications and outlook
Most people with simple fatty liver do well, especially if they undertake the key lifestyle improvements. A minority of people progress to steatohepatitis, fibrosis and cirrhosis, with risks of liver failure and liver cancer. Fatty liver also raises the risk of type 2 diabetes, high blood pressure and kidney disease, and, in people with diabetes, of heart attack, stroke, irregular heart rhythm and death from heart disease.2 The outlook is good when caught early: simple fatty liver is often fully reversible, and even fibrosis can stabilise or improve with sustained metabolic-health change.
When to see a doctor
- See your clinician if liver blood tests are abnormal, or if you have risk factors such as type 2 diabetes, a large waist or raised triglycerides.
- Seek prompt help for jaundice, abdominal swelling or other signs of advanced liver disease.
- Discuss alcohol intake honestly, as it strongly affects the liver.
Summary
- Fatty liver disease (MASLD, formerly NAFLD) is fat in the liver linked to insulin resistance, not alcohol.
- It is very common and usually silent, but can progress to inflammation, scarring and cirrhosis in some people.
- It is both a result and a driver of poor metabolic health, worsening blood sugar and blood fats.
- Reducing sugar, carbohydrate and total fuel (food) intake, plus physical activity and where needed modest weight loss, can clear liver fat.
- Assessing the degree of scarring may be appropriate, and specialists manage more advanced disease.
References
- Rinella ME, Lazarus JV, Ratziu V, Francque SM, Sanyal AJ, Kanwal F, et al. A multisociety Delphi consensus statement on new fatty liver disease nomenclature. Hepatology. 2023;78(6):1966-1986. doi:10.1097/HEP.0000000000000520. PubMed.
- National Institute for Health and Care Excellence. Metabolic dysfunction-associated steatotic liver disease (MASLD): assessment and management. NICE guideline NG49. NICE; published 6 July 2016, last updated 31 July 2026. www.nice.org.uk/guidance/ng49
- 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). J Hepatol. 2024;81(3):492-542. doi:10.1016/j.jhep.2024.04.031. PubMed.
- Keating SE, Hackett DA, George J, Johnson NA. Exercise and non-alcoholic fatty liver disease: a systematic review and meta-analysis. J Hepatol. 2012;57(1):157-166. doi:10.1016/j.jhep.2012.02.023. PubMed.
Each reference was opened and checked against the sentence it supports on 26 October 2026. Guidelines change, so the guideline entries are re-checked whenever the article is reviewed.
Health Shelf, healthshelf.org · Dr Campbell Murdoch, GP, UK · Reviewed October 2026
This is general information, not medical advice. Always speak to a qualified healthcare professional about your own symptoms and treatment, including before changing any medication.
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