mainly olive oil.
The low-fat diet restricted fatty or sugary snacks, limiting fats to less than 30 percent of daily calorie intake.
At the end of a four-year study period, some of the participants in each group still hadn't gone on medication.
At the six-year mark, all the people in the low-fat diet group had gone on diabetes medication, but it wasn't until the eight-year mark that all people in the Mediterranean diet group needed medication.
Diabetes "remission," in which blood sugar levels appear healthy with no signs of diabetes, was rare overall but slightly more common in the Mediterranean group, according to the results published in Diabetes Care.
Avoiding saturated fat, which often comes from red meat, could be important for diabetics, Olansky said.
"Although we don't know exactly what it is about Mediterranean diets that helps control blood sugar, it likely has to do with high levels of fiber, less red meat, and more olive oil and fish, a good source of protein with unsaturated fat," she said.
"The Mediterranean diet represents an easy way to combine healthy foods with taste and flavor," Esposito said. "Most of our patients continue to follow Mediterranean diet, even after the study ended."
People on the Mediterranean diet tended to lose more weight than those on the low-fat diet, which may be because the Mediterranean diet is easier to stick to, Olansky said.
"Patients often ask us what they can do besides medication," Olansky said.
"Often they want to try a lifestyle intervention before medicine, and this is a great example of something you could offer a patient."