The Mediterranean diet is based on the traditional eating habits of Mediterranean countries, which were found to have lower rates of death from cardiovascular disease in the 1960s. Since it is founded on the diets of all of the Mediterranean peoples, there is no single "Mediterranean diet," so the name is a slight misnomer. This diet focuses mainly on fruits, vegetables, grains, nuts, and seeds along with olive oil as the main fat source, and it allows low to moderate consumption of dairy, eggs, fish, and poultry. The Mediterranean diet limits processed foods, red meat, and sweets. Unlike short-term, restrictive diets, the Mediterranean diet is marketed as a more permanent way of life.
The Mediterranean diet is the best way to lose weight and keep it off. Since it is primarily plant-based with healthy additions like lean poultry and fish, this diet makes it fairly easy to shed pounds. Several celebrities, like actress Penelope Cruz and chef Rachael Ray, have touted the Mediterranean diet for helping them reach their goal weights. Besides weight loss, there are many other benefits of eating a Mediterranean diet. For example, its high emphasis on olive oil as a primary fat source has been shown to lower levels of bad cholesterol, thus keeping blood vessels clear. Harvard Medical School also notes that this diet lowers the risk of heart disease, diabetes, some types of cancer, and depression, among other conditions, and it can improve both mental and physical well-being. These benefits are also easier to reach with the Mediterranean diet because it is easier to maintain than its more restrictive counterparts like keto or paleo diets. In short, there is a reason that the Mediterranean diet was rated #1 out of over 30 diets--several times, in fact--by experts at US News and World Report.
There are several ways that the Mediterranean diet is not restrictive enough, which can make it more difficult for many people to lose weight. For instance, it relies heavily on olive oil as a fat source but does not regulate the amount that people use, so using too much of it--at 120 calories and 14 grams of fat per tablespoon--can negate other healthy eating habits. Also, this diet does not control portion sizes or number of calories consumed, and if either of these is too large, it will be very difficult for a person to lose weight. Additionally, some research, such as one large, randomized study published in 2013, has come under suspicion for its imprecision of testing and questionable results. This study found that the Mediterranean diet greatly reduces the risk of heart attacks and strokes, and it was supposed to be groundbreaking for the diet, but both other experts and the study's lead researcher found that many participants had not been truly randomized or supervised, thus invalidating large portions of data. The study's team reanalyzed the results and eventually came to the same conclusion about this diet's health benefits as before, but many doctors and nutritionists are hesitant to recommend--and even outright caution against--the Mediterranean diet due to the research's flaws. The Mediterranean diet is therefore not the ultimate diet. It is not restrictive enough, and the results of the main study backing it up are questionable at best.
Rejecting the premises
More on the Mediterranean diet: https://www.marieclaire.co.uk/life/food-drink/the-mediterranean-diet-687606