Genetic and environmental contributions to obesity

The rapid increase in obesity over the past 2 decades serves as a serious threat to health and quality of life. Data from familial, twin, and adoption studies strongly suggest that genetics contributes to a substantial portion of the variation in body weight and body fatness within a population. Because it is likely substantial changes have occurred in the gene pool over this period, it must be that changes in the environment have increased the susceptibility of obesity in many genetic phenotypes. This article discusses how changes in various environmental factors are contributing toward constant positive energy balance, leading to body weight dysregulation. Efforts aimed at managing obesity should be directed toward modification of the environment.