Obesity: the science behind the management

The prevalence of obesity is increasing in Western and Westernizing countries. The changing environment plays a major role in this increase, particularly the reduction in physical activity. There is also a strong genetic contribution to the development of obesity, although single-gene defect obesity is rare. Neither the environment nor genes is simple to modify. Obesity is an energy-balance disorder, and the human body has evolved to resist any loss of body fat. This biological drive to maintain weight is coordinated through central pathways, with the involvement of many neuropeptides. Thus, dietary restriction will induce changes designed to counter weight loss, including a fall in resting metabolic rate. The management of obesity demands reasonable goals, which focus on metabolic, rather than cosmetic, improvement. As obesity is a complex condition, multiple therapeutic strategies are required. Dietary modification, an increase in physical activity, a reduction in sedentary activity and behaviour modification all form the basis of obesity therapy. Drug therapy options at present are limited and may have a stronger role in weight maintenance. Currently, surgical management of obesity has the best long-term outcomes. Long-term maintenance of weight loss is achieved by few individuals. Those individuals who are successful are able to maintain long-term restrictive eating habits and high levels of physical activity.