Obesity is a health condition resulting from excess body fat. Overweight means having more than the recommended body weight according to one’s height. Being overweight or obese is one of the leading preventable causes of death in the U.S.

More than a third of U.S. adults are obese, according to the most recent data from the National Health and Nutrition Examination Survey. Approximately 20 percent of U.S. children and adolescents ages 2 to 19 are obese. Being overweight or obese raises the risk of coronary heart disease, type 2 diabetes, asthma, high cholesterol, osteoarthritis, high blood pressure, sleep apnea and certain types of cancer.

Obesity causes range from genetic differences in metabolism to socioeconomic factors, such as the unreliable availability of healthy food in disadvantaged areas. Medications, such as those used to treat some psychiatric conditions, can also cause weight gain.

Treatment for obesity may involve diet, exercise, medications and in some cases, surgery.