ABSTRACT
Over the past two to three decades, there has been an increase of body mass relative to height in many countries, pointing to the phenomenon of a worldwide obesity epidemic. This chapter focuses on a number of changes in lifestyle end environment that have run in parallel with the growing prevalence of obesity. Food manufacturers and caterers have encouraged an excessive intake of nutrients by increasing portion sizes and augmenting the sugar content of their products. At the same time, voluntary physical activity has diminished, with industrial mechanization and automation, fewer opportunities for active transportation, and an increase in sedentary pursuits both at work and at home. Dietary compensation for cigarette withdrawal has contributed further to an increase of weight in a substantial segment of the adult population. Moreover, a decrease of lean tissue mass has led to underestimation of the extent of this secular change.
