Diets

Food consumption provides essential and nonessential nutrients in the human body and thereby promotes growth and health. Individual food choice and the potential modification of eating habits are complex issues, influenced by the availability and acceptability of foods.1 The availability of foods depends on physical, political, and economic factors. From the myriad foods that are available or potentially available for consumption, the selection is based on socioeconomic, cultural, and individual factors. Individual foods are parts of diets; diets are characterized by nutrient content, clustering of foods, and temporal consumption patterns. The plethora of diets continually expands, and some diets have been extensively investigated.
We review the underlying rationale for and constituents of the most widely recognized, scientifically explored, and broadly promoted diets (Figure 1). We do not review diets for specific nutritional or metabolic deficiencies or many of the constructed dietary indexes. This review is not intended to detail the clinical efficacy of each diet presented, although we briefly outline some of the well-known potential effects on health and the underlying mechanisms. Even though most (but not all) of the dietary modifications have been driven by the desire to control body weight, we consider important health effects independently of adiposity.