Bmi: Is It Reliable?

Summary

• Bmi: Is It Reliable?
• Calculating Your Bmi
• Where Do These Figures Come From?
• What Is The Problem?
• Ama’s Announcement
• So, what about Bmi?

Bmi: Is It Reliable?

BMI remains the key determining figure to calculate how over- or underweight an individual is. But in June 2023, the American Medical Association issued a statement saying that BMI would not be a reliable measure of obesity… Should still be relying on this figure?

Calculating Your Bmi

Obesity is a growing factor in global health: since 1975, WHO has found that the number of people affected has tripled, and estimates that by 2030, one in seven men and one in five women will be affected by this disease.

Until now, the determining factor for considering whether a person is obese was the calculation of the BMI (Body Mass Index), a simple equation. This figure is easily accessible: to get it, you just have to divide your weight in kilos by the square of your height in meters (for example, if you are 60kg and 1m65, you have to divide 60 by 1,65×1,65). If the resulting figure is between :

Where Do These Figures Come From?

The BMI scale is based on the research of the Belgian mathematician Adolphe Quételet, who lived and worked in the 19th Century. Among his many studies, he looked for a way to describe and measure «the average man». It was in the last quarter of the 20th century, when the medical profession began to face obesity problems, that doctors and insurers sought a way to easily and quickly find an indication of the potential health risks of weight. Quételet’s work resurfaced as one of the possible solutions. In 1972, a study identified this index as being easily applicable because of the simplicity involved in its calculation. The «Quételet scale» was therefore renamed BMI (Body Mass Index) became the main indicator for the health industry.

What Is The Problem?

As early as in 1972, the scientists who proposed the adoption of the BMI as a generalized measure had identified that it was not «fully satisfactory», not applying to all bodies and all cases in the same way.

People who are very muscular, taller or smaller are not necessarily equal when facing this calculation, for example.

Moreover, Quételet’s figures were based on a European white population, not taking into account any genetic differences due to origin or gender.

Studies have shown that BMI underestimates obesity among Asians – in Singapore, national guidelines consider that a person is obese from a BMI of 23 – while Polynesians or Afro-Americans are overestimated on the BMI scale – they will generally display a lower body fat percentage than a person of European origin with the same BMI.

Ama’s Announcement

In June 2023, the American Medical Association, the largest group of doctors and medical students in the United States, issued a statement clarifying the use of BMI for calculating obesity and overweight. The document highlights the usefulness of BMI for a general population measurement, but encourages health professionals to consider other measures (body fat, visceral fat, waist circumference, genetic and/or metabolic factors) in their individual approach to patients.

Is Bmi Still Useful?

As stated in this press release, BMI remains a useful basis for estimating overweight or obesity. It is then up to the doctor or health professional to consider the variables of each patient to determine the approach to follow.

 In conclusion: you should not hesitate to calculate your BMI to see where you stand on the scale. In addition, you can talk to your doctor or health practitioner to assess the situation.