Chronic diseases such as diabetes, cardiovascular diseases, and cancers are known as a substantive worldwide challenge for health systems and are major contributors to mortality and morbidity. According to the World Health Organization, 71% of all deaths and 63.8 % of Disability-Adjusted Life Years (DALYs) are attributed to chronic diseases. The composition of a diet influences health status and affects the occurrence and severity of chronic diseases. As different components of a diet correlate and interact with one another, addressing only individual dietary constituents does not usually help in analyzing the extent to which diets may prevent or contribute to the development or progress of chronic diseases. In recent years, the concept of dietary indices has received more attention by both researchers and clinicians and is used as a means to capture the overall effect of a diet on a specific disease or a group of related illnesses. These indices are nutritionally derived mathematical algorithms which are developed on the bases of useful or detrimental nutrients and/or food groups. Thus, the indices are frequently used to elucidate proper aspects of a specific diet such as quality; diversity; anti-inflammatory, anti-oxidative, and/or anti-glycation potential; and acid load. Examples include the: dietary inflammatory index (DII), dietary total antioxidant capacity (DTAC), healthy eating index (HEI), dietary acid load, and so forth. There is accumulating evidence indicating a link between scores of dietary and nutritional indices and health outcomes.