ABSTRACT
Laval University, Canada 6.1 INTRODUCTION The technological developments that have occurred in the last century have allowed a considerable reduction of the physical demand of daily activities. This has undoubtedly improved the efficiency and productivity of labor but for many individuals, this change in activities has removed the main source of physical stimulation contributing to optimal body functioning. In this context, leisure time physical activities have been considered as the main alternative and have been the object of a lot of advertisement for every individual. Despite this dissemination effort, adequate physical activity participation is not achieved by a majority of people, be it in children or adults, and is considered as an important determinant of overweight and obesity. Besides the tendency of modernity to promote sedentariness, other relevant changes in daily activities have been recently observed and are worthy of consideration as determinants of childhood obesity. As discussed in this paper, the decrease in sleep duration and the increase in activities soliciting mental work also favor significant modifications of energy balance. Thus, beyond the effect of physical activity on body composition, this paper extends the discussion of this global issue to additional activities whose impact on energy balance has been unsuspected until recently.
