The sugar intake of children must be reduced if we want to reduce the burden of fatty liver disease, says cardiologist Dr Ross Walker.

The number of children diagnosed with fatty liver disease could double over the next decade, with already 15 per cent of kids afflicted with the disease, warns an Australian cardiologist.

Fatty liver occurs when excess fat accumulates in the liver cells and can lead to potentially deadly cirrhosis of the liver and possibly Type 2 diabetes if left untreated.

Cardiologist Dr Ross Walker says non-alcoholic fatty liver disease (NAFLD) is already a leading cause of chronic liver disease in children, and he fears this will only worsen as sugar intake continues to rise among kids.

"The figures are saying that about 15 per cent of school kids have fatty liver disease," Dr Walker told AAP.

Unfortunately a child doesn't have to be overweight or obese to have a fatty liver, says Dr Walker, a poor diet is to blame.

"Everyone associates cirrhosis with alcohol and maybe hepatitis but they don't associate being overweight and what you eat," said Dr Walker.

A recent International study published in the Journal of Hepatology found the sweetener fructose used in fizzy drinks, biscuits, cakes and ice cream was linked to inflammation of the liver or non-alcoholic steatohepatitis (NASH) - the most extreme form of NAFLD.

The study of 271 obese children and adolescents with NAFLD found nearly 90 per cent reported drinking soft drinks one or more times a week.

Researchers from the UK and Italy found almost 95 per cent of patients regularly consumed morning and afternoon snacks consisting of crackers, pizza and salty food, biscuits, sweetened yogurt, or other snacks.

Lead researcher Valerio Nobili from the Hepatometabolic Unit Liver Diseases Laboratory at Bambino Gesu Hospital in Rome said it was "plausible" that dietary fructose intake was a potential risk factor for liver disease progression in NAFLD.

In Australia, chronic liver disease claims the lives of an estimated 7000 people a year.

About one-third have non-alcoholic fatty liver disease, and the subsequent rate of progression to NASH is about 30 per cent.

Unfortunately, Dr Walker says, people don't recognise that the liver - the body's "major processing factory" of raw materials - is affected by anything other than alcohol.

He says a healthy liver is a manifestation of a healthy body.

"If you overload it with excessive nutrients the liver can't cope and so it doesn't work as well," Dr Walker said.

A well as a good diet, exercise is also key to preventing a fatty liver.

Australian researchers at the University of Queensland recently demonstrated that exercise therapy reduces liver fat in adults.

"We found that exercise is very effective at reducing liver fat, and liver fat is highly linked to things like insulin resistance, the development of diabetes and other cardiovascular disease risk factors," said Dr Shelley Keating from UoQ's School of Human Movement and Nutrition Sciences.

Dr Shelley and her colleagues are now investigating whether high-intensity interval training can prevent the development of Type 2 diabetes in patients with NASH.