Explainer | What is MASLD? Most common chronic liver disease affects up to 40% of adults

Nalini Lakhani, a Hong Kong secondary school teacher, had never heard of metabolic dysfunction-associated steatotic liver disease (MASLD) until she got her diagnosis. Few people have heard of it, even though it is the most common chronic liver disease worldwide. MASLD is essentially the new term to describe non-alcoholic fatty liver disease (NAFLD). There is a 95 per cent overlap in the diagnostic criteria for the two conditions, says Dr Loey Mak Lung-yi, a Hong Kong-based specialist in gastroenterology and hepatology. Both involve having excessive fat in the liver, considered to be more than 5 per cent of the liver’s weight. The shift in terminology from NAFLD to MASLD began in 2020 as doctors and experts gained a deeper understanding of the disease’s key driver: metabolic dysfunction. That includes conditions such as obesity, diabetes and dyslipidemia, the latter of which is characterised by high levels of fats – or lipids, including cholesterol and triglycerides – in the blood. These factors drive fat to accumulate in the liver, a process known as “hepatic steatosis”, and the disease progresses from there. Presenting with metabolic dysfunction is a positive diagnostic criterion for MASLD, which replaces the process of “diagnosis by exclusion”, Mak says, such as the previous criterion of not drinking, so “non-alcoholic”. Only a small group of people previously diagnosed with NAFLD – about 5 per cent – do not have metabolic risk factors, so they will be reclassified into a separate category. The new terminology also destigmatises the condition by removing the words “non-alcoholic” and “fatty”. Lakhani, aged 58, still uses the word “fatty”, though. “My fatty liver was diagnosed about five years ago,” she says. She ascribes her diagnosis to a stressful work life, not exercising and unhealthy eating habits. Her health deteriorated, and she was also diagnosed with type 2 diabetes in July 2024. “The doctor prescribed medication for it, but I told myself that I would try to be proactive to change my lifestyle instead of taking the meds,” she says. Diabetes and obesity, Mak says, are among the key diagnostic criteria for MASLD, “which is observed in 60 per cent to 70 per cent of individuals with type 2 diabetes and around 70 per cent to 80 per cent of those with obesity”. Having diabetes can accelerate disease progression. MASLD is a common condition affecting between 35 and 40 per cent of the general adult population globally. Highly prevalent in Asia, it is growing rapidly – from 25 per cent of adults in the early 2000s to 33 per cent in 2017. It is expected to rise by up to 20 per cent in the next five years. The trend, Mak says, mirrors the obesity trend, which follows the lifestyle changes that began during the Covid-19 pandemic. Despite the connotations of its name – and the fact that the upwards trend follows the rising levels of obesity – not everyone with MASLD is overweight or obese, Mak says. Even people who are lean can develop MASLD, a demographic that accounts for 10 to 20 per cent of all MASLD cases. Cases range from mild to severe. “Mild” MASLD describes excessive fat without inflammation or fibrosis in the liver. “Moderate” or “at-risk” refers to the presence of excessive fat and inflammation, and significant or advanced liver fibrosis. “Severe” refers to the presence of cirrhosis or liver cancer. It is a significant health concern, Mak says, as MASLD has overtaken several other causes to become the leading cause of liver transplant wait-listing in the West. “We have not yet observed this in Asia-Pacific owing to the lag period of disease,” Mak adds. The danger with MASLD, she warns, is that many people with it are not aware of their condition as it is asymptomatic. She describes the case of a 45-year-old banker who was referred to her clinic with abnormal liver function and an ultrasound showing fatty liver. The woman drank alcohol three to four times a week, three or four glasses of wine each time. She barely exercised. She stood 165cm (5ft 4in) tall and weighed 80kg (176lbs), for a BMI of 29.3kg/m² – in the obese category. She was also hypertensive and had pre-diabetes. Tests showed that she had advanced liver fibrosis. The banker was shocked; she could not believe that she had developed a liver condition bordering on cirrhosis at such a young age. She did realise, though, that her lifestyle was the main reason for the condition, and she could do something to change it. “I encouraged her, [saying] that it was not too late for her to take action as the condition was still reversible, and we set a goal to lose 10 per cent of body weight over the next 12 months,” Mak says. “She stopped dining out and started to prepare meals for herself,” which were low in calories, fat and sugar. “She skipped all sweetened beverages and alcoholic drinks and began running for an hour three times a week.” Six months later, she had lost 6kg, and blood tests showed her liver enzymes were normal. A year later, she was down to 67kg, and a repeat scan showed normal liver fat and a reversal of fibrosis. She has done it all on her own, Mak says, without any pharmacological treatment or surgical intervention, just sheer determination to achieve a clear goal, which is backed by strong scientific evidence. Lakhani is grateful to have been part of a research group at Queen Mary Hospital, where her participation extended the opportunity to further understand MASLD. She downloaded an app onto her phone that tracked the results of her liver scans and her weight and diet, “which made me all the more mindful”, she says. “I started exercising by doing yoga daily and strength training three times a week. I also started eating right by increasing my protein intake to around 70 grams of protein daily. “Thankfully, in six months, my sugar went down to normal, and my liver also showed a very good improvement.” She says she now realises that this approach is a way to cure and prevent MASLD. Mak says in traditional Chinese culture, excess body fat is deemed “wealthy” or a kind of “blessing”. But, when it comes to the liver, she says, “less is more”. Like what you read? Follow SCMP Lifestyle on Facebook, X and Instagram. You can also sign up for our eNewsletter here.

.css-1c6uqr6{color:inherit;font-weight:inherit;font-size:inherit;font-family:inherit;line-height:inherit;overflow-wrap:break-word;}Previously known as non-alcoholic fatty liver disease, MASLD is trending upwards as obesity levels rise, but it can affect lean people too

Previously known as non-alcoholic fatty liver disease, MASLD is trending upwards as obesity levels rise, but it can affect lean people too