In summary . . . Research on Obesity and Overweight

"Over the past several decades, the prevalence of obesity among adults and children in the United States has increased dramatically and is now reaching epidemic proportions. The prevalence of obesity in adults in the United States was 30.5 percent in 1999-2000. More than twice as many adults (nearly 65 percent) were considered to be either overweight or obese. Some 6 million U.S. adults were considered morbidly obese in 2001. In 2002, an estimated 15 percent of all children aged 6 to 19 years were overweight.

Obesity is more common in women, but men are more likely to be overweight. Obesity is especially common among African Americans, American Indians, Native Hawaiians, and some Hispanic populations.

Obesity is the second leading cause of preventable deaths; smoking is the first. Obesity is associated with many significant health problems, including high blood pressure, heart disease, diabetes, stroke, osteoarthritis, sleep apnea, premature death, and decreased quality of life. Even modest weight loss can reduce an individual's risk for these diseases and outcomes.

Obesity is defined as having a body mass index (BMI, weight in kg/height in m2) of 30 or more. For example, a 5'5" woman weighing 180 pounds or more or a 5'11" man weighing 215 pounds or more would be termed obese. Morbid obesity is defined as having a BMI of 40 or more (35 to 40 with medical problems related to obesity). Overweight is defined as having a BMI of 25 to 29.9 (a 5'5" woman who weighs 150 pounds or more or a 5'11" man who weighs 180 pounds or more). A BMI of 20 to 24.9 is considered normal weight, and a BMI under 20 is considered underweight.

In children and adolescents, weight above a normal range has different terms: at risk for overweight and overweight. Being at risk for overweight is defined as a BMI between the 85th and 94th percentile for age and sex; overweight is defined as a BMI at or above the 95th percentile for age and sex." Research on obesity and overweight