Obesity is an abnormally high proportion of body fat. The doctor can often determine if you are obese by looking at your body and assessing the percentage of body fat. Methods of assessing body fat are discussed below.
Measuring your weight in relation to your height is the traditional way of determining whether you are overweight, obese, or at an appropriate weight. Your doctor can often determine if you are overweight or obese by calculating your body mass index (BMI). This can be done by dividing your weight in kilograms by your height in meters squared. Your BMI can easily be calculated using a height and weight table. The BMI calculation does not take into account whether your weight is composed mostly of fat or muscle. Some muscular people may have a high BMI without being overweight or obese.
In addition, there is risk associated with abdominal fat build up, even if your total weight is not high. So measuring the circumference of your waist is also an important measure of whether you need to lose weight.
There are other tests that can estimate your percentage of body fat. The accuracy of these tests varies and some are so expensive that you are not likely to have them at the doctor’s office. When combined with your visual appearance and waist circumference, your BMI can usually provide a valid estimate of whether you are overweight or obese.
Methods to diagnose obesity:
Blood tests can be done to rule out other medical conditions that may cause excess body weight, such as thyroid or adrenal disorders
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Last reviewed February 2017 by Michael Woods, MD, FAAP Last Updated: 2/23/2017