An overview on the nutrition transition and its health implications: the Bellagio meeting

This supplement is based on papers presented at the Bellagio Conference on the Nutrition Transition. The meeting was organised to allow us to assess current lowand moderate-income industrialising countries’ experience related to the nutrition transition and provide ideas for pushing forth a broader public health agenda in this area. More specifically, the meeting focused on changes in patterns of behaviour (diet, smoking, drinking, activity) that lead to rapid increases in obesity, cardiovascular disease (CVD) and cancer. The nutrition-related noncommunicable diseases (NR-NCDs) were once referred to as diseases of affluence. For decades this has not been true among higher-income countries, and as we now show, this is increasingly not the case in the lowerand middleincome countries. Two historic processes of change occur simultaneous to or precede the nutrition transition. One is the demographic transition – the shift from a pattern of high fertility and high mortality to one of low fertility and low mortality (typical of modern industrialised countries). Even more directly relevant is the epidemiological transition, first described by Omran: the shift from a pattern of high prevalence of infectious diseases associated with malnutrition, and periodic famine and poor environmental sanitation, to a pattern of high prevalence of chronic and degenerative diseases associated with urban–industrial lifestyles. A third pattern of delayed degenerative diseases has been formulated more recently (e.g. Olshansky and Ault). Accompanying this progression is a major shift in age-specific mortality patterns and a consequent increase in life expectancy. Interpretations of the demographic and epidemiological transitions share a focus with the nutrition transition on the ways in which populations move from one pattern to the next. Similarly, large shifts have occurred in dietary and physical activity and inactivity patterns. These changes are reflected in nutritional outcomes, such as changes in average stature and body composition. Modern societies seem to be converging on a pattern of diet high in saturated fat, sugar and refined foods and low in fibre – often termed the ‘Western diet’. Many see this dietary pattern to be associated with high levels of chronic and degenerative diseases and with reduced disability-free time. These three relationships are presented in Fig. 1. Human diet and activity patterns and nutritional status have undergone a sequence of major shifts, defined as broad patterns of food use and their corresponding nutrition-related diseases. Over the last three centuries, the pace of dietary and activity change appears to have accelerated, to varying degrees in different regions of the world. Further, dietary and activity changes are paralleled by major changes in health status, as well as by major demographic and socio-economic changes. Obesity emerges early in these shifting conditions as does the level and age composition of morbidity and mortality. We can think of five broad nutrition patterns. They are not restricted to particular periods of human history. For convenience, the patterns are outlined as historical developments; however, ‘earlier’ patterns are not restricted to the periods in which they first arose but continue to characterise certain geographic and socioeconomic sub-populations.