Liver disease linked to obesity and high blood sugar could affect 1.8bn people worldwide by 2050, a study suggests.
Metabolic dysfunction-associated steatotic liver disease, or MASLD, was previously known as non-alcoholic fatty liver disease. It is one of the most common and fastest-growing liver conditions worldwide.
There are now 1.3bn people worldwide living with MASLD, the latest estimates suggest, with about one in six people, or 16 per cent, affected.
That marks a 143 per cent rise in just three decades. In 1990, about 500m people were living with the condition.
By 2023, that figure had risen to 1.3bn. MASLD is projected to affect 1.8bn people by 2050, a 42 per cent rise from 2023.
The findings came from the global burden of diseases, injuries, and risk factors study.
The condition’s prevalence is projected to climb further, driven mainly by global population growth alongside lifestyle changes such as rising obesity and high blood sugar levels.
MASLD was more common in men than women and had the highest prevalence in adults aged 80 to 84. However, the largest numbers affected were younger, at about 35 to 39 in men and 55 to 59 in women.
High blood sugar was the leading driver of MASLD-related health problems globally, followed by high body mass index and smoking, highlighting strong links to type 2 diabetes and obesity.
The global prevalence rate rose to 14,429 cases per 100,000 people in 2023, up 29 per cent from 1990.
Some regions, including north Africa and the Middle East, had disproportionately higher rates of MASLD compared with other regions.
But there have been sharp increases in numbers of people affected in countries across the world.
In the UK, the prevalence rate rose by a third, or 33 per cent, between 1990 and 2023, the biggest increase in western Europe.
The prevalence rate grew by 30 per cent in Australia and 22 per cent in the US.
The study also found that although more people were developing the disease, the overall impact on health, measured in years lost because of illness or death, was stable.
That suggested advances in treatment and care were helping people live longer and healthier, and that the increase in the number of cases was mostly happening in the early stages of the disease.
However, the growing number of cases still means many people are at risk of developing serious complications such as liver cirrhosis or cancer in the future.
MASLD is often linked to being overweight and can usually be treated with lifestyle changes.
It does not usually cause any symptoms, and many people have the condition without realising, according to the NHS. It is usually only discovered when a patient has tests for another reason.
Symptoms may include feeling very tired, feeling generally unwell, and liver pain or discomfort under the right side of the ribs.
The study was led by the Institute for Health Metrics and Evaluation, a public health research institute at the University of Washington in Seattle.
Its authors said the findings highlighted that MASLD was increasingly affecting younger adults, amid worsening health and lifestyles.
The rise in the number of cases underscored the importance of recognising it as a global health priority and of developing policies, awareness campaigns and interventions to mitigate its growing impact and prevent future complications, they said.