ObesityEpidemiology, Etiology, Consequences and Treatment

There are currently 300 million obese persons in the world and about one billion more with a more moderate excess weight problem. Children and adolescents are also affected at unprecedented rates. This pandemic has evolved rapidly over the last 30 years. Higher caloric intake relative to energy expenditure is favored... read moreby obesogenic physical and social environmental conditions leading to obesogenic behaviours. A number of genetic defects causing obesity have also been identified but they are generally rare. Of great importance from a population point of view is the evidence for considerable individual differences in the predisposition to be chronically in positive energy balance. The latter appears to be a consequence of the poor fit between a genome that has evolved under conditions of limited caloric availability but high energy expenditure and our present-day environment of abundant food supply but low requirements for physical activity.

Excess weight, which essentially means expanded adipose tissue and triglyceride storage, carries significant health risks, particularly for metabolic disorders such as diabetes but also for cardiovascular diseases, a number of cancers, orthopedic problems, psychiatric disorders and quality of life. When the excess weight is severe enough, the risk of premature death is increased.

Treatment modalities include behavior modification techniques to reset dietary intake at a level commensurate with the level of energy expenditures. Pharmacotherapy is typically used to provide support to the behaviour modification prescription. Bariatric surgery is becoming the treatment of choice for the most severe obesity cases. However, while obesity specialists are quite skilled at inducing major weight losses in their patients, they are less successful at preventing weight regain. The latter is one of the most complex problems as it requires lifelong re-alignment of one’s lifestyle against biological and environmental opposing forces.

The aim of this series is to provide an evidence-based review of the epidemiology of obesity and associated morbidities in adults and children, the etiology of obesity and the multiplicity of its causes, the biological and environmental determinants of the current epidemic, the various treatment modalities of obesity and current thinking concerning its prevention.