One in five children may already have fatty liver disease, global study finds

A study spanning 17 countries estimates that nearly one in five children in community settings has metabolic dysfunction-associated steatotic liver disease, with rates rising among adolescents as obesity increases.

A large international study has found that fatty liver disease is far from rare in children, with researchers estimating that roughly one in five youngsters in the community may already have the condition. The analysis, which drew on data from 38 centres in 17 countries across five continents, points to metabolic dysfunction-associated steatotic liver disease, or MASLD, as a growing paediatric health problem rather than one confined to adulthood.

MASLD is the current medical term for what was previously called non-alcoholic fatty liver disease. It develops when fat builds up in liver cells in people with metabolic risk factors such as obesity or insulin resistance, while alcohol intake remains low. In its earliest stages it may cause no symptoms, but over time it can progress to inflammation, scarring and, in some cases, cirrhosis or liver cancer. That is why doctors and researchers have become increasingly concerned about children who develop fatty liver at a young age: the earlier the process begins, the longer there is for liver injury to accumulate.

The scale of the new research marks it out from earlier work. More than 9,300 children and adolescents aged 6 to 18 took part, with participants recruited both from community settings and from hospitals. All underwent vibration-controlled transient elastography, or VCTE, a painless scan that can estimate both fat in the liver and stiffness linked with fibrosis. Studies in the paediatric literature have already suggested that VCTE is a reliable non-invasive option for identifying steatosis and scarring, and that it can track changes over time alongside shifts in weight and blood markers.

The headline finding is stark. In children recruited outside hospital settings, the prevalence of MASLD was 17.60%, rising to 20.97% after age standardisation. Among hospital patients, the figure was 58.03%, or 52.34% when age-adjusted. That gap matters because it shows how heavily hospital-based studies can overstate the burden in the wider population, even while revealing just how concentrated the disease is among children already living with metabolic risk. The research also found wide regional variation, with community prevalence highest in South America, followed by North America and Asia.

The study suggests the trend is worsening in adolescents. When researchers compared children assessed between 2017 and 2020 with those seen from 2021 to 2024, MASLD was more common in the later period, except among adolescents of normal weight or below. That points to obesity as the main driver of the increase. Older age, excess weight and raised liver enzymes were all linked with both fatty liver and fibrosis, and children with more severe fat accumulation were more likely to have more advanced scarring. For clinicians, that strengthens the case for using routine blood tests to identify at-risk children and VCTE to assess them further without resorting to biopsy. For parents and public health officials, it is a warning that paediatric fatty liver is becoming a mainstream metabolic disease with consequences that may last into adulthood.