Obesity is a medical term that refers to excessive amounts of body fat. Body mass index (BMI) is a measurement that is used to categorize persons as either overweight or obese. This measure is calculated by a mathematical equation involving both height and weight. For adults, a BMI above 25 generally refers to being overweight, while a BMIabove 30 refers to obesity. Excessive amounts of body fat may increase the risk of developing medical conditions such as high blood pressure and diabetes. While genetics and hormonal changes may play a role in body weight, overweight and obesity are likely related to an imbalance between calories consumed and calories expended by the individual.
While lifestyle changes, such as increased physical activity and dietary modifications, play a significant role in weight loss, some individuals may be candidates for other treatment options when weight loss does not occur as expected. Medications available with a prescription for longterm weight loss include sibutramine (Meridia) and orlistat (Xenical). Sibutramine works by decreasing the time to feeling full after eating. Orlistat prevents the absorption of fat in the intestines. Orlistat (Alli) is also now available over-the-counter as a lower strength than prescription strength Xenical.