"The groundwork of all happiness is health." - Leigh Hunt

How useful is body mass index (BMI)?

Do you already know your BMI? Increasingly, people know them, like they know their levels of cholesterol.

BMI = (weight in kilos x 703) / (height in inches x height in inches).

So, now that you already know your BMI, is it value knowing? What are you going to do with it?

What does your BMI mean?

To understand what your BMI means, it's helpful to take a step back and understand what it's measuring and why it's measured.

BMI is a calculation of your size that takes under consideration your height and weight. Many years ago, I remember using charts that told you to seek out your height on the left side after which select yours from the alternatives listed under small, medium, or large “frame” sizes. Slide your finger to the appropriate to see “Ideal Weight”. .

These charts come from actuarial statistics, calculations that life insurance firms use to find out your possibilities of living to old age based on data from 1000’s of individuals. These charts were cumbersome to make use of, and it was never clear find out how to judge an individual's “frame size.”

BMI does something similar: it shows the connection between your height and weight as a number that doesn't rely on frame size. Although BMI dates back greater than 200 years, it is comparatively recent when it comes to health.

What is a standard BMI?

A traditional BMI is between 18.5 and 25; An individual with a BMI between 25 and 30 is taken into account chubby. And an individual with a BMI greater than 30 is taken into account obese. An individual is taken into account underweight if the BMI is lower than 18.5.

As with most measures of health, BMI is just not an ideal test. For example, results could also be skewed by pregnancy or excess muscle mass, and might not be an excellent measure of health in children or the elderly. So, why does BMI matter? In general, the upper your BMI, the greater your risk of developing a spread of conditions related to being chubby, including

  • Diabetes
  • Arthritis
  • Liver disease
  • Many forms of cancer (akin to breast, colon and prostate)
  • High blood pressure (hypertension)
  • Cholesterol increase
  • Lack of sleep.

According to WHOAround three million people worldwide die every year from being chubby or obese. In addition, individuals with a better BMI often feel higher physically and psychologically, independent of a specific disease, once they lose more weight.

Should we stop giving a lot “weight” to BMI?

Probably. Research shows that BMI alone often misclassifies metabolic health, which is linked to how much fat an individual has and the way it's distributed. And, BMI could be particularly unreliable while pregnant. the playerAnd Elderly.

Actually, it should come as no surprise. BMI, as a alone Measurements won’t be expected to discover cardiovascular health or disease. The same goes for cholesterol, blood sugar, or blood pressure as a single measurement. And while cardiovascular health is very important, it's not the one measure of health! For example, the study described above didn’t consider conditions that may be relevant for a person with an elevated BMI, akin to liver disease or arthritis. Also, BMI could also be more useful in predicting future relatively than current health. People who’re healthy and chubby or obese usually tend to develop diabetes or other negative health outcomes over time, based on studies. This one And This one.

And there's one other problem: Current BMI definitions of chubby or obesity were mostly based on white populations. Yet body composition, including percent body fat or muscle mass, can vary by race and ethnic group. Therefore, BMI may help predict health status in white people, but could also be less accurate for people of other racial and ethnic groups.

For example, obesity is defined by standardized measures of BMI. Overestimation of risk among black individuals And Consider it less for people of Asian descent.. This could lead on to suboptimal counseling and treatment, and ultimately increase health care disparities. The World Health Organization and the National Institutes of Health recommend different BMI cutoffs for chubby and obesity in people of Asian descent. Changes to BMI cutoffs are also being really useful for other ethnic groups.

The bottom line

As a single measure, BMI is clearly not an ideal measure of health. But it's still a useful start line for vital conditions which might be more likely when an individual is chubby or obese. In my opinion, knowing your BMI is an excellent idea. But additionally it is vital to acknowledge its limitations.

Follow me on Twitter. @RobShmerling