Height-to-waist ratio is now believed to be a better measure of obesity than body mass index (BMI). CBS News medical contributor Dr. Holly Phillips reports on the research behind the change.The body mass index (BMI), or Quetelet index, is a heuristic proxy for human body fat based on an individual's weight and height. BMI does not actually measure the percentage of body fat. It was devised between 1830 and 1850 by the Belgian polymath Adolphe Quetelet during the course of developing "social physics". Body mass index is defined as the individual's body mass divided by the square of his or her height. The formulae universally used in medicine produce a unit of measure of kg/m2. BMI can also be determined using a BMI chart,which displays BMI as a function of weight (horizontal axis) and height (vertical axis) using contour lines for different values of BMI or colors for different BMI categories. The waist-to-height ratio (WHtR) of a person is defined as the person's waist circumference, divided by the person's height. The WHtR is a measure of the distribution of body fat. Higher values of WHtR indicate higher risk of obesity-related cardiovascular diseases; it is correlated with abdominal obesity.
The WHtR should not be confused with the Waist–hip ratio (WHR), which has also been used to measure body fat distribution.
A 2010 study that followed 11,000 subjects for up to eight years concluded that WHtR is a much better measure of the risk of heart attack, stroke or death than the more widely used body mass index.
Conversely, WHtR was not a predictor for new-onset diabetes melitus in at least one study.
For people under 40, a WHtR of over 0.5 is critical; for people in the age group between 40 and 50 the critical value is between 0.5 and 0.6, and for people over 50 the critical values start at 0.6.
The WHtR should not be confused with the Waist–hip ratio (WHR), which has also been used to measure body fat distribution.
A 2010 study that followed 11,000 subjects for up to eight years concluded that WHtR is a much better measure of the risk of heart attack, stroke or death than the more widely used body mass index.
Conversely, WHtR was not a predictor for new-onset diabetes melitus in at least one study.
For people under 40, a WHtR of over 0.5 is critical; for people in the age group between 40 and 50 the critical value is between 0.5 and 0.6, and for people over 50 the critical values start at 0.6.
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