The incidence of obesity in the United States is reaching alarming levels. Nearly 2 out of 3 (64.5 percent) U.S. adults are overweight or obese (BMI greater than 30). The percentage of U.S. adults classified as obese doubled between 1980 and 2000. Perhaps even more alarming, the percentage of overweight and obese children has tripled over the last 30 years.

Overweight and obese individuals are at increased risk for diabetes, heart disease, hypertension, musculoskeletal conditions, stroke, endometrial, breast, prostate and colon cancers, poor female reproductive health, and depression, among other conditions. For every 2-pound increase in weight, the risk of developing arthritis is increased by 9-13 percent. Type 2 diabetes, a disease previously associated with adults, is now being seen in children. Obesity is a greater trigger for health problems and increased health spending than smoking or drinking. Individuals who are obese have 30 to 50 percent more chronic medical problems than those who smoke or drink heavily. Obesity is estimated to lead to 400,000 deaths annually.

At the opposite end of the spectrum lie the other diseases of weight regulation: anorexia nervosa, idiopathic failure to thrive and disease cachexia. Anorexia nervosa, primarily a psychiatric disorder that involves the weight regulation system, has an incidence of 0.5 to 1 percent in adolescent girls and young women, and a mortality rate of 10 percent. Failure to thrive in infants is responsible for up to 5 percent of pediatric hospital admissions. Involuntary weight loss, or cachexia, is commonly associated with cancer, AIDS, and many infectious diseases. It contributes significantly to the morbidity and mortality of these diseases.

Together, these disorders of weight regulation account for a large part of the national health care dollar. According to the US Surgeon General, in 2000, costs related to obesity totaled $117 billion. Obesity is associated with 39 million lost work days per year, 239 million restricted-activity days, 90 million bed days, and 63 million annual physician visits.