The most common version of the “modern” Mediterranean diet was presented by Dr Walter Willett of Harvard University’s School of Public Health in the mid-1990s.
Based on eating foods typical of Greece and southern Italy in the early 1960s, the diet emphasizes fruits and vegetables, olive oil as the principal source of fat, dairy products (principally cheese and yogurt), fish and poultry, eggs, and wine.
Total fat in this diet is 25% to 35% of calories, with saturated fat at 8% or less of calories.
In greater detail the diet includes high olive oil consumption, high consumption of legumes such as beans, high consumption of unrefined cereals, high consumption of fruits and vegetables, moderate consumption of dairy products, moderate to high consumption of fish, low consumption of meat and meat products, and moderate wine consumption.
More than any other food ingredient, olive oil represents the Mediterranean diet. Olive oil is nutritious and contains very high levels of monounsaturated fats, most notably oleic acid. Epidemiological studies suggests that a higher proportion of monounsaturated fats in the diet is linked to a reduction in coronary heart disease risk.
There is also considerable clinical data to show that antioxidants in olive oil can provide additional heart health benefits such as regulation of cholesterol and keeping blood pressure low.
The diet is often cited as beneficial for being low in saturated fat and high in monounsaturated fat and dietary fiber.
For more information, see the following link:
Mediterranean Diet- Mayo Clinic