Fast Five Quiz: Management of Obesity

Elif A. Oral, MD; Evelyn S. Marienberg, MD


December 19, 2022

BMI has been shown to be a useful measure for assessing population-based mortality and disease-specific morbidity; however, there are major limitations of using BMI alone to diagnose obesity in an individual. BMI cannot distinguish weight associated with muscle vs fat and does not distinguish body fat distribution, which is a known determinant of metabolic risk. Specifically, measuring fat distribution helps detect higher-risk individuals because increased visceral fat predicts the development of metabolic syndrome, type 2 diabetes, and total and cardiovascular mortality risk better than total body fat alone.

Population studies have shown a high specificity of using BMI cutoff values to diagnose obesity but low sensitivity to identify adiposity, which overlooks approximately half of people with excess fat. This can be particularly worrisome in the older population, where a reduced lean body mass (sarcopenia) may be mistaken as a healthy BMI.

Anthropometric techniques are available to estimate the distribution of body fat; these include waist circumference alone, waist-to-hip ratio, and the ratio of waist circumference divided by height (waist-to-height ratio). These measures have been associated with the risk of developing heart disease, type 2 diabetes, and other chronic diseases associated with obesity.

Combining waist circumference with BMI provides a means of incorporating weight distribution into measures of obesity. However, waist circumference is most useful in individuals with a BMI ≤ 35, according to Bray and colleagues.

Learn more about obesity management.


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