A team of international researchers, including Dr Matt Sabin from the Murdoch Childrens Research Institute in Melbourne, has found a mother's body mass index (BMI) powerfully predicts whether children will develop type 2 diabetes.

Dr Sabin said a mother's BMI was found to be more accurate than family history of the disease or genetics.

The father's BMI was found to be irrelevant.

Doctors will now be able to more accurately predict type 2 diabetes using maternal BMI together with the child's BMI, than by using the child's weight alone.

Dr Sabin said it was important to determine which children were most at risk so doctors could decide who needed early intervention.

Interventions included helping families adopt a healthier lifestyle.

Dr Sabin said a quarter of Australian children were overweight and the family environment had a strong influence.

Type 2 is the most common form of diabetes.

"While it usually affects mature adults, more young people, and even children, are being diagnosed," says the Australian Diabetes Council website.

Type 2 diabetes occurs when the pancreas no longer produces enough insulin. It can lead to blindness, amputation of lower limbs, kidney failure, heart disease and death.

Dr Sabin and his colleagues studied 1800 children over 20 years.

The research, published in the Journal of Pediatrics, also found eating adequate amounts of fruit appeared to reduce the risk of type 2 diabetes. AAP