| Abstract: | The definition of obesity, a condition of excess body fat, is relatively arbitrary and usually based on an approximation of body fat--the body mass index (BMI, Quetelet's index = weight in kg/[height in m]2). A BMI of 30 kg/m2 or more is a commonly-used criterion for defining obesity in both sexes, even though at equal BMI female subjects are consistently fatter than male subjects. In many industrialised countries obesity is a very common disorder and the chronic diseases associated with it are major killers. Even more worrying is the increasing prevalence of obesity in developing countries. Although the remedies seem simple--ie, eat less and exercise more--overall the treatment of obesity has been disappointing because our understanding of the causes of the disorder is incomplete. Current strategies for the prevention and treatment of obesity are discussed in the accompanying article by Professor Garrow, and any future successes in this area, for both individuals and populations, will depend on basic research into the causes of chronic energy imbalance. In this article, we will highlight new insights into the pathophysiology of obesity. |
