People who are obese and have type 2 diabetes are often told that overeating and a sedentary lifestyle are the main causes of their condition.

However, Australian researchers including Professor Grant Morahan from Perth's Harry Perkins Institute of Medical Research, have helped to discover hidden "obesity genes" that could change how type 2 diabetes is diagnosed and treated.

Diabetes experts meeting at a conference in Melbourne today are discussing the findings from the pioneering "Gene Mine," following a presentation about the discovery.

Professor Grant Morahan from the Perkins worked with Dr Sof Andrikopoulos, from Melbourne University, who measured body weight, blood glucose and insulin sensitivity in pre-clinical models from 8 genetic backgrounds.

They found several genes that together increased susceptibility to obesity and the body's inability to respond to naturally occurring insulin.

"This will set the scene for researchers to find new treatments for type 2 diabetes," Professor Morahan said.

"We need to stop oversimplifying type 2 diabetes as a condition caused by excessive weight and a lack of exercise because there are many genetic factors that predispose people to diabetes," he said.

Professor Morahan said that it wasn't single genes that caused diseases but interaction between multiple genetic variants.

He said the diabetes discovery was likely to be the first from the Gene Mine.

"We are also looking at genes that prevent or delay melanoma, genes that cause heart attacks in young people and ones that can prevent dementia," Professor Morahan said.