ABSTRACT
Many contemporary textbooks that discuss the connection between physical activity and health often begin by delineating how the principal infectious diseases of the past, for example cholera, tuberculosis, polio and diphtheria, have been replaced as the foremost causes of premature mortality (death) by non-infectious diseases associated with lifestyle changes. The most important lifestyle changes are those that have accompanied the ‘modernization’ of populations-a reduction in fruit and vegetable intake, an increase in the consumption of refined, ‘fast’ foods that tend be high in saturated fats, sugar and salt, an increase in psychosocial stress and a reduction in physical activity. The reduction in physical activity has been attributed to changes in occupational activity, i.e. fewer manual jobs, the introduction of labour-saving devices in the household and garden, the proliferation of the motor car and the sudden and dramatic increased availability of sedentary leisure-time activities such as computer games.
