The Mediterranean diet is the lucky definition given by Ancel Keys of the food habits of some populations in the Mediterranean area. Dietary styles of this region may widely vary between coasts and inland. The total fat content of diets may vary from less than 30% in the traditional diet of Southern Italy to about 40% in the island of Crete. Carbohydrate and fibre rich foods also vary in terms of energy content, type and amount of sugars. Also proteinrich foods have large variations being mostly of vegetable origin rather than animal. Finally the original description of this diet also brings to mind the extensive physical activity, mainly related to work and outdoor leisure activities that prevailed in these populations until the sixties. Changes toward transition diet, the meaning of functional food and life style changes in the area at present are also discussed.