(Newser) – Huge numbers of American children have a liver disease that used to be seen mainly among adult alcoholics—and most of them don't know it, researchers warn.

Around 10% of children are now believed to have fatty liver disease, which can lead to cirrhosis and liver failure in some cases, the Wall Street Journalreports. Around 40% of obese children have the condition, but its prevalence is rising even as obesity rates level off; the number of normal-weight children with fatty livers has also surged over the last 20 years, studies show.

"This is just really worrisome to have this number of children who have a disease this severe," says a pediatrics professor whose research has found that the prevalence of fructose in Western diets could be partly to blame.

The disease has no symptoms and public health experts are debating introducing widespread screening for it.

Little is known about how the disease progresses into adulthood and for now, treatments for it and associated illnesses are limited: Doctors recommend weight loss through diet and exercise and treating inflamed livers with Vitamin E. (In other health news, a recent study found that one fruit rules supreme when it comes to lowering your diabetes risk.)