The industrial period (1800–1945) saw the development of the ‘industrialised society’ with the accompanying problems of overcrowding, poor diet, poor public health measures and inad-equate medical facilities and care. Infectious diseases were responsible for a high proportion of premature deaths. However, this trend became reversed in the ‘nuclear/technological’ period, which Blair (1988) identified as from 1945 until the present. The major improvement in public
health measures and medical advances meant that infectious diseases were becoming less
common in ‘advanced’ societies. However, health problems were merely shifted in terms of
causes and outcomes. The major causes of premature mortality have now become ‘lifestyle
related’, such as coronary heart disease, with risk factors such as cigarette smoking, poor diet and lack of physical activity (Paffenbarger et al.1994). As Paffenbarger et al.put it, ‘both energy intake and energy output are determined primarily by individual behavior’ (1994: 119). In short, humans have now adopted lifestyles in industrialised countries that were quite unknown until very recently in terms of human evolution (see Box 1.1 and Figure 1.2). This is not to say, of course, that ‘health’ has necessarily deteriorated; far from it in some cases, although this depends on the definition and measurement of health. Lifespan itself has