Normal weight BMI or abdominal circumference? Which measure overweight more correctly determined
Anyone who is concerned about losing weight usually first consults the body mass index (BMI). Its value is based on the formula "weight in kilograms divided by the ratio of height in meters". It can be determined with the help of a calculator or BMI calculators on the Internet.
If the value is between 18.5 and 24.9, a person is considered normal weight according to the guidelines of the World Health Organization (WHO). Overweight starts at 25, obesity at 30.
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As simple as the categorization is, as influential it is, because the BMI also has social weight, for example, in the Verbeamtung: In some states, a value of over 27.5 for police officers or over 30 for teachers is often considered an exclusion criterion.
The BMI, experts agree today, however, sorts people too quickly into a grid. Because the respective value says nothing about the individual composition of the body, whether for example the fat portion is larger or the muscle mass.
"Very muscular policemen or athletes can have a BMI of over 30," says Munich diabetologist Harald Schneider, for instance. "Arnold Schwarzenegger’s BMI was 32 in his -best days."
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Abdominal girth more meaningful than body mass in-dex
In addition, it is undisputed that people of advanced age may well weigh a little more in order to have reserves in periods of illness. Therefore, there is the so-called desirable BMI, which may be about the age between 55 and 64 after all 23 to 28.
The BMI is nevertheless useful as approximate reference point. However, it would be better to use a value that takes into account the amount of fat in the body and where this fat is located. Because abdominal fat (or "visceral fat") is particularly dangerous.
It produces various hormones that increase the risk of cardiovascular diseases such as heart attack or stroke.
Doctors therefore consider the abdominal circumference to be more meaningful than the BMI. It should be less than 88 centimeters for women and 102 centimeters for men (best measured with a normal tape measure in the morning and at navel height when exhaled). The abdominal circumference can also be related to the hip circumference and also the body height: Experts speak of waist-to-hip ratio (WHR) or waist-to-height ratio (WHtR).
WHtR can usually be determined more accurately, as there is more likely to be measurement error when measuring hip circumference than when determining height. For the waist-to-height ratio (abdominal circumference divided by height), overweight starts at a value of 0.51 for people under 40 years of age. Older may have 0.01 points more per year of life, up to -a -maximum value of 0.61.
Increased WHtR despite BMI below 25
Someone who puts a belly in front of him, but is tall and rather gaunt, can show a significantly increased WHtR, while his BMI is below 25 – which would lull the person in question into a false sense of security.
The question "Do I need to lose weight?" should therefore not be based on BMI alone. Fat distribution also matters – as does minimizing other health risk factors, such as high blood pressure, elevated cholesterol and blood sugar levels, and smoking.
If there are no problems, even an increased BMI is not necessarily a cause for concern.