Obesity: from genes to behaviour

An increase in the consumption of highly palatable foods coupled with a reduction in the amount of voluntary exercise undertaken has contributed to the rising prevalence of obesity. However, despite the obvious environmental influences, there is considerable evidence to support a genetic component to weight gain. In some people, particularly those who are severely obese, genetic factors play a major role in the development of their obesity and associated complications. Studies into the genetic basis of obesity have yielded insights into the mechanisms involved in the regulation of weight. We now understand that weight is regulated by neural mechanisms that regulate appetite and energy expenditure and that disruption of these pathways can result in severe obesity in some patients. These studies provide a starting point for investigating patients with severe obesity and may ultimately guide the development of more rational targeted therapies.