This literature review aims to quantitatively define the Mediterranean diet (MedDiet) by food groups and nutrients. The study searched databases such as PubMed, MEDLINE, Science Direct, and the University of South Australia Library Catalogue for articles that defined the MedDiet in at least two of four ways: general descriptive definitions, diet pyramids/numbers of servings of key foods, grams of key foods/food groups, and nutrient and flavonoid content. The results show that the MedDiet typically includes three to nine serves of vegetables, half to two serves of fruit, one to 13 serves of cereals, and up to eight serves of olive oil daily. It provides approximately 9300 kJ of energy, with 37% from total fat, 18% from monounsaturated fat, and 9% from saturated fat, and 33 g of fiber per day. The review highlights the need for more consistent definitions and reporting of key nutrients and bioactive compounds to better understand the mechanisms of the MedDiet's health benefits.This literature review aims to quantitatively define the Mediterranean diet (MedDiet) by food groups and nutrients. The study searched databases such as PubMed, MEDLINE, Science Direct, and the University of South Australia Library Catalogue for articles that defined the MedDiet in at least two of four ways: general descriptive definitions, diet pyramids/numbers of servings of key foods, grams of key foods/food groups, and nutrient and flavonoid content. The results show that the MedDiet typically includes three to nine serves of vegetables, half to two serves of fruit, one to 13 serves of cereals, and up to eight serves of olive oil daily. It provides approximately 9300 kJ of energy, with 37% from total fat, 18% from monounsaturated fat, and 9% from saturated fat, and 33 g of fiber per day. The review highlights the need for more consistent definitions and reporting of key nutrients and bioactive compounds to better understand the mechanisms of the MedDiet's health benefits.