People can reduce their risk of type 2 diabetes by improving the overall quality of their diet, a new study has found.

This effect is independent of other lifestyle changes, such as exercising more or losing weight.

The study was carried out by scientists at the Harvard School of Public Health in the US, who defined diet improvements as more fruit, vegetables and whole grains and less sugary drinks and saturated fats.

Using a healthy eating index to score participants, they found that people who improved the quality of their diet by 10% over a four-year period, reduced their risk of type 2 diabetes by around 20%, compared to people who made no improvements in their diet during the same period.

"We found that diet was indeed associated with diabetes independent of weight loss and increased physical activity. If you improve other lifestyle factors you reduce your risk for type 2 diabetes even more, but improving diet quality alone has significant benefits," commented lead researcher, Dr Sylvia Ley.

She said these findings are important because people often find it difficult sticking to diets that restrict calories.

"We want them to know if they can improve the overall quality of what they eat - consume less red meat and sugar-sweetened beverages, and more fruits, vegetables and whole grains - they are going to improve their health and reduce their risk for diabetes," she said.

The study also found that it did not matter how good or bad a person's diet was in the beginning.

"Regardless of where participants started, improving diet quality was beneficial for all," Dr Ley added.

Details of these findings were presented at the American Diabetes Association's 74th Scientific Sessions in San Francisco.