Obesity is likely when an individual's body mass index (BMI) is 30 or higher. Your body mass index is calculated by dividing your weight in kilograms (kg) by your height in meters (m) squared.

BMI Weight status
Below 18.5 Underweight
18.5-24.9 Normal
25.0-29.9 Overweight
30.0-34.9 Obese (Class I)
35.0-39.9 Obese (Class II)
40.0 and higher Extreme obesity (Class III)

For most people, BMI is a reasonable estimate of body fat. However, BMI doesn't directly measure body fat, so some people, such as muscular athletes, may have a BMI in the obese category even though they don't have excess body fat. Ask your health care provider if your BMI is a problem.

When to see a doctor

If you think you may be obese, and especially if you're concerned about weight-related health problems, see your doctor or health care provider. You and your provider can evaluate your health risks and discuss your weight-loss options.

May. 13, 2014

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