A new study finds that even if you don't lose weight or boost exercise, following a Mediterranean diet can help prevent the onset of Type 2 diabetes.

In the Spanish study, people at risk for heart disease who followed a diet of fruits, vegetables, whole grains, fish, and fats from nuts or olive oil were about 30 per cent less likely to develop diabetes over a four-year period than those who ate a low-fat diet.

The research was a subanalysis of last year's influential , involving 7,447 subjects at high risk for cardiovascular disease. Researchers from Universidad de Navarra found that subjects who ate a Mediterranean diet had a 30 per cent greater reduction in the risk of heart attack, stroke, or death from cardiovascular disease than those who ate a low-fat diet. The new paper, published this week in the , looked at the development of diabetes among 3,541 subjects who didn't have diabetes at the beginning of the study.

Even just adding olive oil to your diet resulted in a health boost, the study suggests. Participants who added fats from extra-virgin olive oil were 40 per cent less likely to develop diabetes during the study compared with those who followed a low-fat diet.

Recent evidence from Harvard Medical School and Brigham and Women's Hospital in Boston also found that middle-aged women who follow a Mediterranean diet may live healthier, longer lives. Scientists evaluated the diets and medical records of 10,670 women and found that after 15 years those women who followed a Mediterranean diet were 40 per cent more likely to survive to age 70 or over without heart disease, diabetes, or other chronic disease.