Throughout the twentieth century there has been a marked acceleration of processes of modernisation and urbanisation in developing societies. Cities in the Third World, and especially urban centres of South America, have swollen with an influx of migrants from the countryside. In many cases these migrants have been driven by failing rural economies and natural disasters, but of equal importance is the allure of city life. The urban centre holds out the promise of ‘the good life ’; it offers the possibility of achieving the kind of lifestyle and affluence symbolised in media imported from the industrial centres of Europe and North America.

Concomitantly, developing societies have been progressing through that transformation of patterns of morbidity and mortality known as ‘the epidemiologic transition ’. Rates of infectious and parasitic disease have remained high, but rates of chronic disease, and especially coronary heart disease (CHD), have climbed at an alarming rate. For example, in urban Brazil in 1930, infectious and parasitic diseases accounted for half of all deaths, while CHD accounted for only 12%. By 1980, infectious and parasitic diseases accounted for 12% of all deaths, while CHD accounted for 33% (James et al., 1991).

How are we to account for this transition? Conventional wisdom would argue that as modernisation and urbanisation proceed, life becomes more sedentary and diets become more sodium- and fat-laden, which in turn increases blood pressure and unfavourable lipid profiles, and leads to CHD.