Mediterranean diet

The Mediterranean diet is a concept first proposed in 1975 by American biologist Ancel Keys and chemist Margaret Keys. It is inspired by the eating habits and traditional foods of Greece, Italy, the Mediterranean coasts of France and Spain, as well as the Levant as observed in the late 1950s to early 1960s. The diet is distinct from Mediterranean cuisine, which encompasses the diverse culinary traditions of Mediterranean countries, and from the Atlantic diet of northwestern Spain and Portugal, albeit with some shared characteristics. The Mediterranean diet is the most well-known and researched dietary pattern in the world.

While based on a specific time and place, the "Mediterranean diet" generically describes an eating pattern that has been refined based on the results of multiple scientific studies. It emphasizes plant-based foods, particularly unprocessed cereals, legumes, vegetables, and fruits; moderate consumption of fish and dairy products (mostly cheese and yogurt); and low amounts of red meat, refined grains, and sugar. Alcohol intake is limited to wine (typically the red variety) consumed in low to moderate amounts, usually with meals. Olive oil is the principal source of fat and has been studied as a potential health factor for reducing all-cause mortality and the risk of chronic diseases.

The Mediterranean diet is associated with a reduction in all-cause mortality in observational studies. A 2017 review provided evidence that the Mediterranean diet lowers the risk of heart disease and early death; it may also help with weight loss in obese people. The Mediterranean diet is one of three healthy diets recommended in the 2015–2020 Dietary Guidelines for Americans, along with the DASH diet and vegetarian diet. It is also recognized by the World Health Organization as a healthy eating pattern.

Mediterranean cuisine and its associated traditions and practices were recognized as an Intangible Cultural Heritage of Humanity by UNESCO in 2010 under the name "Mediterranean Diet". The Mediterranean diet is sometimes broadened to include particular lifestyle habits, social behaviors, and cultural values closely associated with certain Mediterranean countries, such as simple but varied cooking methods, communal meals, post-lunch naps, and regular physical activity.

The Mediterranean diet is low in saturated fat with high amounts of monounsaturated fat and dietary fiber. One possible factor is the potential health effects of olive oil in the Mediterranean diet. Olive oil contains monounsaturated fats, most notably oleic acid, which is under clinical research for its potential health benefits. The European Food Safety Authority Panel on Dietetic Products, Nutrition and Allergies approved health claims on olive oil, for protection by its polyphenols against oxidation of blood lipids and for the contribution to the maintenance of normal blood LDL-cholesterol levels by replacing saturated fats in the diet with oleic acid (Commission Regulation (EU) 432/2012 of 16 May 2012). A 2014 meta-analysis concluded that an elevated consumption of olive oil is associated with reduced risk of all-cause mortality, cardiovascular events and stroke, while monounsaturated fatty acids of mixed animal and plant origin showed no significant effects.

The United States 2015–2020 national guidelines devised a "Healthy Mediterranean-Style Eating Pattern" from the Mediterranean diet patterns and its positive health outcomes. It was designed from the "Healthy U.S.-Style Eating Pattern", but recommends more fruits and seafood, and less dairy. A 2020 review of research on the Mediterranean diet indicated that it may optimize cardiovascular health.

A 2017 review found evidence that practice of a Mediterranean diet could lead to reduced risk of cardiovascular diseases, overall cancer incidence, neurodegenerative diseases, diabetes, and early death. A 2018 review showed that practice of the Mediterranean diet may improve overall health status, such as reduced risk of non-infectious diseases, may reduce total costs of living, and may reduce costs for national healthcare. A 2016 review found similar weight loss as other diets.

The Mediterranean diet is included among dietary patterns that may reduce the risk of cardiovascular diseases. A 2013 Cochrane review found limited evidence that a Mediterranean diet favorably affects cardiovascular risk factors. A 2013 meta-analysis compared Mediterranean, vegan, vegetarian, low-glycemic index, low-carbohydrate, high-fiber, and high-protein diets with control diets. The research concluded that Mediterranean, low-carbohydrate, low-glycemic index, and high-protein diets are effective in improving markers of risk for cardiovascular disease and diabetes, while there was limited evidence for an effect of vegetarian diets on glycemic control and lipid levels unrelated to weight loss. A Mediterranean diet was recommended in 2016 as a means of lowering apolipoprotein B.