The term “diet” and “dieting” can have surprisingly different meanings to different people. Therefore, before we delve into the papers that discuss living healthily, we must define our terms. There are two main types of diets: elimination diets and restriction diets.
Elimination diets are the most famous diets; they include Adkins, paleo, carnivore, vegetarian, vegan, etc. These diets work by eliminating a part of the diet and substituting more of something else.
Restriction diets have existed much longer than elimination diets and have received renewed interest in the past 5 years. Calories and/ or eating times are restricted in these diets while no foods are necessarily eliminated from this diet. Restriction diets include global caloric restriction, fasting, and intermittent fasting with its numerous subtypes as seen in figure 1.
These diets are not mutually exclusive. For example, the low carbohydrate diet restricts many processed carbohydrates and also decreases the amount of calories eaten in a day.