By Andrew M. Seaman NEW YORK (Reuters Health) – Without cutting back on calories, adopting a Mediterranean diet rich in extra-virgin olive oil may protect people at high risk for heart disease against diabetes, a new study found. Researchers who analyzed data on more than 3,500 people at an increased risk for heart disease found those who were put on a Mediterranean diet were about 30 percent less likely to develop diabetes over the next four years, compared to those assigned to a general low-fat diet. “Randomized trials have shown that lifestyle interventions promoting weight loss can reduce the incidence of type 2 diabetes, however, whether dietary changes without calorie restriction or increased physical activity also protect from diabetes development has not been evaluated in the past,” Dr. Jordi Salas-Salvado wrote to Reuters Health in an email.