The population approach to prevent NCDs, articulated by Rose[^1] in his article Sick individuals and sick populations, aims at shifting the distribution of its risk factors for the whole population, therefore affecting everyone regardless of their risk. Rose highlighted the need to measure and understand factors related to interpopulation differences in the distribution of risk factors (social phenomena and social determinants or environmental factors), instead of focusing on factors related to interindividual differences within a population (classic behavioural risk factors and genetics). Analyses of the health consequences of a tragic historical period in ==Cuba== during the past three decades8 have shown population-wide loss of 4–5kg in weight in a relatively healthy population was accompanied by a 50% reduction in diabetes mortality and a 30% mortality reduction from coronary heart disease. Furthermore, a rebound in body weight was associated with an increased diabetes incidence and mortality, and a halting in the decline in mortality from coronary heart disease. Other example: North Karelia Project in Finland. In the 60s, people in this area has the highest rates of coronary heart disease in the world during the 60s. > The question shifted from “Why did this individual develop CVD?” to “Why do population rates of CVD vary so much between East Finland and other parts of the world?”. Based on this concept, the North Karelia Project (which included consultations from Geoffrey Rose himself) designed a large-scale intervention that included partnership with a previously reluctant food industry, subsidies for the production of healthier foods (produce) and large-built environment changes. The results of this project were so encouraging that it was expanded to the entire country of Finland in 5 years and led to large reductions in cardiovascular mortality of around 80% from 1970 to 2006. “Urban environments present unique opportunities for research and policy evaluation of population approaches to prevention. By definition cities are dense, and characterised by substantial man-made components of their environments and by frequent social interactions. These characteristics make cities excellent candidates for policy interventions on social and physical factors affecting large numbers of people. In addition, cities are internally heterogeneous, with large within city variation in social and physical environments, which have been showntobeassociatedwithNCD” (Franco et al., 2015, p. 1) “These four urban environment domains may very importantly have a direct relationship with the well-known and well-studied individual NCD risk factors, namely tobacco use, physical inactivity, harmful use of alcohol and unhealthy diets.” (Franco et al., 2015, p. 2) > “Differences across areas or neighbourhoods are not ‘natural’ but rather result from specific policies (or from the absence of policies)” (Franco et al., 2015, p. 3) [^1]: Rose G. Sick individuals and sick populations. Int J Epidemiol 1985;14:32–8.