What Are Your Dietary Options?
Vegetarian
Considered by many to be the gold standard for human dietary practice, the key reason for this diet is usually ethical, religious or environmental; not primarily health based. It's very difficult but not impossible to be both vegetarian and healthy. That's why in practise most vegetarians are not very healthy, despite what they might personally claim.
Physiologists and biochemists never recommend a vegetarian diet. It's a rod for your own back, and not supported by modern research. Vegan diets are distincly unhealthy and should be avoided. We need animal proteins and fats for our best health.
General Mixed Diet
The low-fat diet recommended in the Dietary Guidelines, has no health benefits: we're not going to do that. Perhaps by eating a little more fat, and by eating far less carbohydrates, people might be able to avoid the long term damage that becomes metabolic syndrome. This would only be a slight variation on what many people are doing anyway. The diet does not tell us to eliminate any food from our diet. It's a small change.
But, if over a lifetime you've damaged your metabolic system, perhaps you need to choose a more dramatic dietary option.
Mediterranean Diet
The Mediterranean diet is a modern nutritional recommendation originally inspired by the dietary patterns of Greece, Southern Italy, and Spain in the 1940s and 1950s. The principal aspects of this diet include proportionally high consumption of olive oil, legumes, unrefined cereals, fruits, and vegetables, moderate to high consumption of fish, moderate consumption of dairy products (mostly as cheese and yogurt), moderate wine consumption, and low consumption of non-fish meat products.
There is tentative evidence that the Mediterranean diet lowers the risk of heart disease and early death. In trials of the Mediterranean diet against the standard American diet, the Mediterranean diet always performs better. There's a clue.
Olive oil may be the main health-promoting component of the diet. There is preliminary evidence that regular consumption of olive oil may lower all-cause mortality and the risk of cancer, cardiovascular disease, neurodegeneration, and several chronic diseases.