ABSTRACT
This chapter looks briefly at some of the techniques, qualitative and quantitative, that have been used to study the prevalence of obesity and to assess responses to the treatment of this condition. In particular, it emphasizes that determinations based on excess body mass and the body mass index can lead to incorrect perceptions of the prevalence of obesity in both muscular individuals and some indigenous populations with unusual limb lengths. Further, it underlines that a failure of body mass to decrease over the course of an exercise-based rehabilitation programme does not necessarily prove the ineffectiveness of regular physical activity as a means of reducing body fat content.
