Nearly two-thirds of the United States population is overweight. There are many ways to determine if a person is overweight, but experts believe that a person's body mass index (BMI) is the best way to assess an adult's weight in relation to their height.

• A BMI from 18.5 to 24.9 kg/m2 is considered normal.
• Adults with a BMI of 25 to 29.9 kg/m2 are considered overweight. There are exceptions. For example, an athlete may have a higher BMI but not be overweight.
• Adults with a BMI of 30 to 39.9 kg/m2 are considered obese.
• Adults with a BMI greater than or equal to 40 kg/m2 are considered extremely obese.
• Anyone more than 100 pounds overweight is considered morbidly obese.

A person with a high BMI may have a normal amount of body fat if they have a lot of muscle tissue. However, the risk of death and disease is increased for adults who are overweight and obese.

For information on calculating your BMI, see: Body mass index

Related topics:

• Obesity
• Unintentional weight gain
• Weight management

Klein S, Fabbrini E, Romijn JA. Obesity. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 36.