Animal research has well established that a link exists between variations in corticosteroids and the proneness to excess body fat accumulation. Accordingly, it is known that adrenalectomy is an efficient approach to counteract weight gain in most animal models of obesity. In humans, the association between variations in corticosteroids, its stress-related environmental effects and the predisposition to obesity is more difficult to demonstrate. In this paper, we propose that this relationship is accentuated by globalization and modernization which favour a labour context imposing additional stress and changes in life habits promoting a positive energy balance. Our main hypothesis is that the increase in knowledge-based work, and the decrease of quality and duration of sleep both induce an increase in cortisolaemia and glycaemia instability, which results in an increase in food intake, a reduction in energy expenditure and body fat gain. The authors of this paper believe that, from a socioeconomic perspective, globalization leads every nation of the world in conflict with itself and may consequently represent a real problem. On one hand, there are preoccupations related to productivity and money making. On the other hand, people have to adopt a daily lifestyle leading to hyperphagia and decreased energy expenditure in order to maintain their economic competitiveness.