Fatty Liver Has a New Name
What Is MASLD and Why Does It Matter?

Perhaps a routine blood test showed that your liver enzymes were "a bit raised". Or maybe you had a scan for something else entirely and the report mentioned a fatty liver, almost in passing. Many of my clients come to me with this exact story, usually followed by the same puzzled question: "But I hardly drink, so why is my liver fatty?"

That’s a good question, and the answer explains why the condition has recently been given a new name. What used to be called non-alcoholic fatty liver disease, or NAFLD, is now known as metabolic dysfunction-associated steatotic liver disease, or MASLD. It is quite a mouthful (Liver UK helpfully points out that MASLD is said as one word, rhyming with "dazzled"), but the new name tells us far more about what is actually going on.

Why Did the Name Change?
In 2023, liver specialists and patient groups from around the world agreed on a new set of terms. The old name had two problems. Firstly, "non-alcoholic" described the condition by what it was not, rather than by what was driving it. Secondly, most of the people who took part in the consensus process felt that the words "non-alcoholic" and "fatty" carried stigma.

"Steatotic" simply means that fat has built up inside the liver cells. "Metabolic dysfunction" points towards the cause, which lies in how the body handles and stores energy. The more serious, inflamed form of the condition, previously called NASH, is now called MASH.

The UK is following suit. In July 2026, NICE renamed its guideline to use the terms MASLD and MASH, and the NHS website currently uses both the old and new names. So, if you see NAFLD on one letter and MASLD on another, they are describing the same thing.

So, What Exactly Is MASLD?
A healthy liver contains very little fat. MASLD is the term used when excess fat has built up in the liver and there is at least one sign that metabolic health is under strain. Under the international definition there are five of these signs:

• carrying extra weight, particularly around the middle (a waist measurement above 80cm for women or 94cm for men is one of the markers used); 
• raised blood glucose, prediabetes or type 2 diabetes; 
• raised blood pressure; 
• raised triglycerides; 
• and low HDL cholesterol.

If that list looks familiar, that’s because these are the same features we talk about with insulin resistance and heart health, hence the new name.

It is also pretty common. A large review published in 2023 estimated that around 30% of adults worldwide are affected, and the figure was closer to 38% in the most recent studies it included. Liver UK estimates that MASLD affects about one in four adults in the UK, and the NHS notes that many people have it without realising.

"But I Hardly Drink"
Your liver is the body's main processing hub for both fat and sugar, and this is where insulin comes in. When cells become less responsive to insulin, known as insulin resistance, fat tissue releases more fatty acids into the bloodstream and many of these end up in the liver. At the same time, the higher insulin levels that accompany insulin resistance encourage the liver to make new fat of its own from surplus carbohydrate.

That does not mean alcohol is irrelevant. The new classification recognises that metabolic factors and alcohol can both contribute in the same person, and there is now a separate category for exactly that. 

Can You Have MASLD at a Healthy Weight?
Yes. In a large analysis of studies from 24 countries, around 40% of people with the condition were not living with obesity, and almost a fifth were classed as lean. European guidelines note that people of a healthy weight who have MASLD tend to have more insulin resistance, more fat stored around the abdominal organs and less muscle than their peers. Genetics play a part too.

Hormones are relevant too. The NHS lists PMOS (formerly known as PCOS) and being over 50 among the factors that make MASLD more likely. A 2023 analysis of 12 studies found that women who had been through the menopause had around 2.4 times the odds of having a fatty liver compared with women who had not. These were snapshot-style studies, so they cannot prove cause and effect, but for midlife women and those with PMOS it is one more reason to keep an eye on metabolic health.

Why It Is About More Than Your Liver
The NHS describes four stages. Most people only ever have the first, where fat has built up but the liver is not damaged. In a smaller number of people the fat triggers inflammation (MASH), which can lead to scarring (fibrosis) and, eventually, cirrhosis.

The wider picture matters just as much. A meta-analysis of 36 studies involving 5.8 million people found that those with a fatty liver had a 45% higher risk of heart attacks, strokes and other cardiovascular events. Another, covering more than 500,000 people, found just over double the risk of going on to develop type 2 diabetes.

These are observational studies, and researchers are still debating how much of the extra risk comes from the liver itself and how much from the risk factors that travel with it. Either way, cardiovascular disease, rather than liver disease, is the leading cause of death in people with MASLD. That is why a fatty liver deserves to be taken seriously as an early signal about metabolic and heart health.

How Is It Found?
Usually by accident. According to the NHS, MASLD does not usually cause symptoms, although some people notice tiredness, feeling generally unwell or discomfort under the right side of the ribs. It tends to come to light when blood tests or a scan are done for another reason.

It is also worth knowing that normal liver blood tests do not give the all-clear. NICE specifically advises clinicians not to rely on routine liver blood tests to rule the condition out. If your GP suspects MASLD, they will ask about alcohol, check your weight and waist measurement, and may arrange further blood tests or an ultrasound scan. They may also check for scarring, for example with a blood test called the ELF test, which features in NICE guidance.

If you recognise yourself in any of this, or you have type 2 diabetes, PMOS, raised blood pressure or raised cholesterol and have never had your liver checked, it is worth a conversation with your GP.

The Encouraging Part
The NHS is clear that healthy lifestyle changes can reduce the build-up of fat in the liver and help repair damage or stop it getting worse. Unless the condition has progressed, these changes are usually the only treatment needed. Its advice is to eat a healthy, balanced diet, be active for at least 150 minutes a week, lose weight if you are overweight, keep alcohol to no more than 14 units a week and not smoke.

European guidelines add that, for people living with overweight, a sustained weight loss of 5% or more is the target recommended to reduce liver fat. New medicines for more advanced disease are also being assessed for NHS use, and these are a matter for your GP or liver specialist.

What you will not find in any of this guidance is a liver detox, a cleanse or a miracle supplement. What matters is the everyday pattern of how we eat, move and live, and that is exactly what I will be covering in the rest of this month's blogs.

Need Some Support?
If you have been told you have MASLD, or you are concerned about your liver, your GP should always be your first port of call for testing, diagnosis and monitoring. Alongside that medical care, personalised nutrition and lifestyle support can help you turn general healthy-eating advice into realistic changes that suit your life. Why not book in a free call?