Mostly vegetables, fruits, nuts, grains, olive oil and some protein - fish and a bit less poultry. Little red meat but a few glasses of red wine. Coupled with regular exercise, there have been records of very long lives lived. The diet is also part of a culture and way of life that enjoys food and dining with family and friends more than many cultures. No doubt there is a health benefit in your mental well being.
The Mediterranean diet is probably the closest to how we eat(merely by food preference). Italian food makes me very happy. I could survive on a Caprese salad alone. Fresh tomato, basil, herbs and olive oil and fresh mozzarella cheese -and it all has to be fresh-is an indescribable taste. We soon added grilled lobster and red wine, for full on Mediterranean.