Obesity and the environment
This chapter examines the way in which the evolution of interactions between humans and their environment have shaped the global obesity epidemic currently being observed. It traces how changes in the work and home environment, an increasing use of motorised transport for mobility, and processes of population urbanisation have led to declines in physical activity. These trends have been accompanied by an increase in the availability of affordable, energy dense food, to create an environment of a ready availability of energy yet few opportunities to expend it. Such an environment is the opposite of that for which the human species is genetically adapted; in the past there would have been selection pressures that favoured those individuals who were most efficient at maximizing the efficiency of their energy intake, whereas now such traits are precisely those which are associated with unwanted weight gain.
In: Clinical Obesity in Adults and Children (3rd ed): Peter G Kopelman, Ian D Caterson, William H Dietz (eds), Blackwell, Oxford, pp Ch 32, pp. 440-451