Abstract
The size and rapidity of the recent increase in the prevalence of obesity is paralleled only by the massive media interest in the causes and implications of these changes and the myriad number of proposed solutions. The availability of information on obesity is overwhelming, but there seems to be common consensus on three points; that obesity is an important public health problem, that the problem is getting worse and that the solution is simple: eat less and exercise more. And yet, although the changing prevalence is a recent phenomenon, obesity itself is not a new public health issue. In the classic paper reprinted in this edition of the journal, Breslow1 noted in 1952 that a substantial proportion of Americans were overweight and that weight control was a ‘major public health problem’. Despite recognition of the increasing levels of obesity, and the knowledge that it is caused by excess energy intake and decreasing levels of physical activity, obesity remains a poorly understood phenomenon. There are profound gaps in our knowledge about the pathophysiological pathways underlying weight gain and in the effectiveness of approaches to tackle the rising prevalence. Breslow's1 paper provides a platform for discussing some of these contemporary issues.