Efforts to help obese children become more active while improving their diet may reduce the amount of fatty tissue in their livers, researchers said.

They said there are currently no drugs against fatty liver disease, which after years can develop into cirrhosis even among young patients.

They added that there is evidence that gradual weight loss is the best way to reduce fatty liver disease, while sudden and significant weight loss may harm liver function and lead to liver failure.

The researchers began a study to determine whether a 12-week program that included nutritional education and an hour of exercise twice weekly would have any effect on fatty liver in a group of 73 obese adolescents. At the start of the study, 52% of the sample had fat on the right side of the liver and 48% had fat on the left side.

After the program, the prevalence of fatty liver disease on both sides decreased significantly to 29%.

The fat around the abdomens of obese adolescents decreased in an average way, as their body mass index decreased and their weight decreased by 48%, while the weights of another 48% remained the same, and their weight increased by 4%.

An important aspect of the findings, Damaso and colleagues note, is the prevalence of fatty liver disease among obese adolescents.