The dietary pattern typical of the Mediterranean area has been set to the famous term "Mediterranean Diet". Potential health effects of the Mediterranean Diet have increased the interest of the scientific community to increase awareness of foods that are part of this dietary pattern and its composition. Several authors observed that the Mediterranean had a lower mortality from cardiovascular disease, and suspected that this was due to food pattern, so that they have conducted several studies to evaluate dietary intake to try to define the eating habits of the area.
The term "Mediterranean diet" defines a set of dietary habits practiced in the 60s by countries in the Mediterranean. The first attempt to describe this dietary pattern was Ancel Keys and colleagues, who studied the food intake of seven countries: Finland, Greece, Italy, Japan, Yugoslavia, USA and Holland. Studying the feeding observed:
- A high intake of cereals in Italy (the largest after Japan) and fruit in Greece.
- The amount of fat consumed was variable between the countries but was qualitatively constant in the Nordic countries and the United States was the predominant saturated fat, while in Southern European countries dominated the unsaturated fats: olive oil mainly in Greece and Italy, and sunflower oil and olive Yugoslavia.
- The total lipid in the Mediterranean countries provide between 25 and 37% of energy.
- Alcohol consumption was variable, as there were differences among the seven countries studied and between the cohorts in each country. Wine was the main source of alcohol in Italy (70 g / day) and in some Yugoslavian populations. studied
Thus highlighting the high consumption of cereals and alcoholic beverages in Italy, Greece and the high consumption of fruit and olive oil.
Analyzing food consumption in the 60s (1961-63) by the Food Balance Sheet shows a marked difference between the dietary pattern of the countries of the Mediterranean area and northern countries. Populations of the Mediterranean countries had a greater amount of energy in the form of grain, had a higher intake of fruits and vegetables, while a smaller amount of energy provided by the meat, fish, dairy, fat, alcoholic beverages and sweets.
In the study, conducted between 1963 and 1965 in Europe, the total fiber intake in half the countries studied (Holland, Belgium, Luxembourg, Germany, France, Netherlands and Italy) was around of 21g/day; cohort of southern Italy was in first place with an average consumption of 24.4 g / day, with one notable difference from the cohort of northern Italy, with 18.2 grams of fiber per day. This study also provided important data on the characteristics of the fats of the Mediterranean diet: in northern Italy and in other northern European countries the use of butter, margarine and other fats (especially animal) was quite often, while in southern Italy, stressing the use of olive oil as the main source of fat (49 g per day about 26 g / day in northern Italy and 10 g / day in France). The southern Italian diet contained 28% of total energy as fat, while in Luxembourg, the Netherlands and Belgium respectively fats provided 45%, 39% and 43% of total caloric intake. Due to the high consumption of olive oil in the south of Italy the monounsaturated / saturated was by far the highest, being 2.29, compared with the countries of northern Europe, which had ratios of 0, 62 to 1.01.
The study also stresses the importance of plant foods as an integral part of the diet of the Mediterranean region and the importance of olive oil as the main source of fat.
All these studies and observations have allowed to clearly define what is currently understood by Mediterranean Diet: a diet rich in foods of plant origin (cereal products, fruit and vegetables, legumes and nuts), low in saturated fat type, with a preponderance of monounsaturated fatty acids, mainly thanks to olive oil, significant amounts of omega-3 fatty acids, low cholesterol intake, plenty of antioxidant vitamins, pro-vitamins and phenolic compounds and adequate amounts of fiber.
Nuts are part of this dietary pattern, and therefore formed part of the normal agricultural fields Mediterranean.