BMI: A Flawed Standard

The BMI was introduced in the early 19th century by a Belgian named Lambert Adolphe Jacques Quetelet. He was a mathematician, not a physician. He produced the formula to give a quick and easy way to measure the degree of obesity of the general population to assist the government in allocating resources. In other words, it is a 200-year-old hack.

BMI: It is often misidentified as a body-composition assessment, when it is simply a ratio of a person’s weight and height.

BMI = Weight (kg)/Height² (m)

While BMI can provide a general overview of weight status at a population level, it should be interpreted with caution on an individual level !!!

Visual Reality vs. BMI

In the world of body composition,LEFT with visible body fat is classified as 'Healthy' due to a BMI below 25.

Meanwhile RIGHT, with higher muscle mass and visible abs, is labeled 'Overweight' simply because their BMI exceeds 25.

This striking example exposes the inherent flaws in using BMI as a measure of health and demonstrates the need for a more accurate and comprehensive approach.

A lot of this probably feels like old news to experienced health coaches and exercise professionals.

The scientific community has long understood the limitations of BMI, but BMI has been able to withstand these criticisms because it’s so widely used and provides a good rough estimate at the population health level.

The truth is, BMI is probably not going away any time soon. It’s free, efficient and provides a means of assessing large groups of people.

It’s long been used to track disease risk factors in large populations—from diabetes, stroke and heart failure to the risk of hospitalisation and death from COVID-19—and is firmly entrenched in the research in these areas and clinical practice.

Continued reliance on the BMI means doctors don't feel the need to use one of the more scientifically sound methods that are available to measure obesity levels.

Those alternatives cost a little bit more, but they give far more reliable results.

This is the first time that an association like the AMA (American Medical Association) has come out and said that, from a clinical perspective, physicians need to look at BMI alongside other measures, as it’s not the most reliable indicator of health status on its own

Because the majority of people today lead fairly sedentary lives and are not particularly active, the formula tacitly assumes low muscle mass and high relative fat content. It applies moderately well when applied to such people because it was formulated by focusing on them.

But it gives exactly the wrong answer for a large and significant section of the population, namely the lean, fit and healthy.

Quetelet is also the person who came up with the idea of "the average man". Averages measure entire populations and often don't apply to individuals.

Breaking Free from Weight Stigma:

Imagine you’ve been told by your doctor that you have obesity because your BMI crossed a somewhat arbitrary threshold established by a mathematician more than 50 years ago.

The emotional and psychological toll that may have on an individual because of the weight stigma and lack of size inclusivity in modern society was one of the concerns that drove the AMA to discourage physicians from telling patients they have overweight or obesity based on this single value.

It should be about individual’s health habits, what they eat, how they move, how they manage stress and how well they sleep, all of which have a tremendous impact on their overall health.

Many people who are categorised as having overweight or obesity may show very healthy profiles in terms of having normal blood sugars or normal blood pressure and may not have the conditions frequently associated with overweight and obesity.

Another issue with the use of BMI centers on the classification categories, which are underweight, normal, overweight, obesity and extreme obesity. It is true that as a person’s BMI goes up, they tend to show a higher risk of certain health conditions.

However, BMI has several limitations that hinder its effectiveness:

Limited Measurement

BMI only considers a person's weight and height, disregarding other important factors such as muscle mass, bone density, and overall body composition. As a result, individuals with higher muscle mass may be classified as overweight or obese, even if they have low body fat levels.

Individual Variations

BMI does not account for individual variations in body shape, proportions, or distribution of fat. Two people with the same BMI can have different body compositions, making it an insufficient measure of overall health.

Lack of Context

BMI fails to consider other significant indicators of health, such as blood pressure, cholesterol levels, or waist circumference. Health risks associated with weight can vary depending on an individual's overall lifestyle, genetics, and other factors that BMI alone cannot capture.

Cultural and Ethnic Bias

The BMI scale was originally developed using data primarily from white European populations. As a result, it may not accurately reflect the diverse body types and proportions of different ethnicities and cultures

Health vs. Appearance:

BMI solely focuses on weight-related health risks without considering factors like physical fitness, dietary habits, or overall well-being. Health is a multifaceted concept, and relying solely on BMI may oversimplify it's assessment.

It makes no allowance for the relative proportions of bone, muscle and fat in the body. But bone is denser than muscle and twice as dense as fat, so a person with strong bones, good muscle tone and low fat will have a high BMI.

Thus, athletes and fit, health-conscious people who work out a lot tend to find themselves classified as overweight or even obese.

At manalifestyle.in, I go beyond the limitations of BMI and focus on a holistic approach that considers individual functional capabilities and diverse aspects of health. Our MISSION is to help clients achieve their maximum fitness potential while embracing international standards and promoting a comprehensive understanding of well-being.