Lifestyle modification in the management of obesity.

The World Health Organization has labeled obesity a global epidemic (1). In the United States, the prevalence of obesity (body mass index [BMI] ≥30 kg/m2) doubled from 15% in 1980 to 30% in 2000 (2). Despite the recent discovery of genetic factors that regulate body weight, an increase of this magnitude cannot be attributed to changes in our genes. The eating and activity habits of Americans have changed significantly during that time period and are the more likely culprits behind the nation’s fattening. Some have labeled ours a “toxic environment,” characterized by heavily advertised and readily available high-calorie foods, large portion sizes, and technological advances that implicitly discourage physical activity (3).