A world-first discovery by Australian scientists about the cooking temperature of rice could impact the eating habits of millions of people.

The findings could help scientists and researchers breed crops with a lower glycaemic index (GI).

Lower GI foods could help diabetics control blood sugar levels and help combat obesity and cardiovascular disease.

"We now know the DNA sequences in the genes in rice that determine what the cooking qualities and what the glycaemic index of the rice will be," professor Robert Henry, of the Centre for Plant Conservation Genetics at Southern Cross University in Lismore, said.

"A food with a high GI is undesirable with regards to diabetes, weight control, obesity and cardiovascular disease."