A clash between modern foods and ancient genes is linked with the development of chronic health problems from diabetes to heart disease, according to a study.

Australian specialists in nutrition and anthropology argue that differences between modern and ancient diets underpin the dramatic increase in these diseases. In what has been dubbed a "bold new theory," RMIT University (Melbourne, Australia) associate professor Neil Mann said humans' ancient genes could not keep pace with the rapidly changing food supply.

"Modern humans are still based genetically on the dietary pattern our hunter-gatherer ancestors survived on millions of years ago," says Mann, who co-wrote “Origins and Evolution of the Western Diet: Health Implications for the 21st Century,” published in the American Journal of Clinical Nutrition.

"Yet just 10,000 years ago, in our more recent past, the arrival of agriculture shifted our diet away from lean meat and plants that were low in fat, high in protein, vitamins and minerals," he wrote.

"Our genetic make-up has not had time to adjust." The most significant changes were sparked by the industrial revolution in the 18th century with the milling of flour, fast food in the 1950s and the arrival of ready-to-eat foods high in fat and carbohydrates.

"Approximately 75% of the energy consumed in our modern diet now comes from foods that have no resemblance to those we ate pre-agriculture," he said.

"These new foods are refined cereals, refined sugars, refined vegetable oils and alcohol." Food loaded with vitamins and minerals had been replaced with "empty calories" - which Mann defines as highly refined products with little nutritional value.

More than 85% of cereals consumed contained highly processed refined grains, and about 75% of daily salt intake was added to processed foods by manufacturers.

A 400% increase in sodium consumption had corresponded with a 400% drop in potassium in the modern diet -- a shift that could contribute to strokes and gastro-intestinal-tract cancers.

Australians consume more than 43kg of sugar each a year, and intake of margarine and salad and cooking oils had soared by 410% and 130%, respectively, in 90 years. A diet high in saturated fats adversely affected the heart and had come at the expense of Omega3 -- a good fat that could reduce the risk of inflammatory and autoimmune diseases. The modern diet was also lower in protein and higher in carbohydrates, which could increase the risk of obesity and Type 2 diabetes.

The research was distributed but reportedly not funded by Meat and Livestock Australia.