Because the BMI was never intended to be used to assess an individual's fitness but instead the general population's, Keith Devlin at NPR concludes that it is not a reliable indicator of obesity. Furthermore, BMI does not consider people with large amounts of muscle mass, as it classifies them as overweight.Continue Reading
While BMI is a good screening tool, it is an ineffective and inaccurate diagnostic tool that ignores both age and gender and does not distinguish between fat and muscle mass, states WebMD. For example, elderly people who have lost muscle mass may appear as normal. BMI also fails to account for differences in where fat is located and stored; fat around the waist is considered more dangerous than fat gathered at the hips or buttocks.
Devlin also criticizes how BMI promotes the belief that the differences between underweight, healthy, overweight and obese are distinct and sharp categories, which is untrue. Instead of relying on BMI, WebMD suggests measuring the waist circumference to provide a more accurate assessment of overall health. Medical practitioners should not use BMI as a shortcut but instead examine a patient's body fat percentage, family history, eating patterns and activity levels to determine whether or not someone is obese.Learn more about Medical Ranges & Levels