Nutrition transition is the shift in dietary consumption and energy expenditure that coincides with economic, demographic, and epidemiological changes. Specifically the term is used for the transition of developing countries from traditional diets high in cereal and fiber to more Western pattern diets high in sugars, fat, and animal-source food.
The nutrition transition model was first proposed in 1993 by Barry Popkin, and is the most cited framework in literature regarding the nutrition transition, although it has been subject to some criticism for being overly simplified. Popkin posits that two other historic transitions affect and are affected by nutritional transition. The first is the demographic transition, whereby a pattern of high fertility and high mortality transforms to one of low fertility and low mortality. Secondly, an epidemiological transition occurs, wherein a shift from a pattern of high prevalence of infectious diseases associated with malnutrition, and with periodic famine and poor environmental sanitation, to a pattern of high prevalence of chronic and degenerative diseases associated with urban-industrial lifestyles is shown. These concurrent and dynamically influenced transitions share an emphasis on the ways in which populations move from one pattern to the next. Popkin used five broad patterns to help summarize the nutrition transition model. While these patterns largely appear chronological, it is important to note that they are not restricted to certain periods of human history and still characterize certain geographic and socioeconomic subpopulations. The first pattern is that of collecting food, a characterization of hunter-gatherers, whose diets were high in carbohydrates and low in fat, especially saturated fat. The second pattern is defined by famine, a marked scarcity and reduced variation of the food supply. The third pattern is one of receding famine. Fruits, vegetables, and animal protein consumption increases, and starchy staples become less important in the diet. The fourth pattern is one of degenerative diseases onset by a diet high in total fat, cholesterol, sugar, and other refined carbohydrates and low in polyunsaturated fatty acids and fiber. This pattern is often accompanied by an increasingly sedentary lifestyle. The fifth pattern, and most recently emerging pattern, is characterized by a behavioral change reflective of a desire to prevent or delay degenerative diseases. Recent and rapid changes seen in developing countries from the second and third pattern to the fourth is the common focus of nutrition transition research and desire for policy that would emphasize a healthier overall diet characterizes the shift from the fourth to the fifth pattern.