You've been asking for its return... for three years. Merry (early) Christmas.
Body Mass Index, more commonly known as BMI. You've probably heard of it. You might have even done a quick search and calculated your own. However, in recent years, more and more studies have challenged the use of BMI as an accurate indicator of health.
So, today we’re looking into BMI, and asking does your BMI really matter?
First things first, what is your BMI?
The body mass index is a measure of your body fat based upon your height and weight.
You can work out your own BMI using the following equation:
BMI = WEIGHT / (HEIGHT)2
Based on your result, you can be classified into several categories:
Underweight – BMI below 18.5
Healthy weight – BMI between 18.5 and 24.9
Overweight – BMI between 25 and 29
Obese – BMI above 30
Of course, if going by this, you want your BMI to be between 18.5 and 24.9.
But what if you’re not?
According to science, it might not be that big of a deal.
A study conducted by UCLA revealed that despite having overweight or obese BMI scores, tens of millions of people were, in fact, a healthy body weight.
On the flip side, 30% of those who have a ‘healthy’ BMI would not be considered as healthy at all if other health data was taken into account, such as overall fitness levels, where their fat is stored etc.
Why is there such a discrepancy?
There are a number of reasons why BMI cannot be trusted, for example:
BMI cannot distinguish between muscle and fat. Therefore people with a high muscle mass can be labelled as ‘overweight.’
BMI does not take into account where the fat is being carried. Those with a ‘healthy’ BMI might store their fat around their middle, which would be more dangerous than someone with a higher BMI who had a more even distribution of fat.
Gender is not taken into account, which can have an impact on BMI scores.
There are many other reasons why BMI might not be the best option when it comes to working out your levels of body fat.
This begs the question, why do we still use BMI at all?
Is there any point at all?
BMI might not be the most accurate on an individual basis, but it can help us to look at trends when we consider it in terms of large populations. It is also a quick, easy and very inexpensive way to at least get an indication of where you are at regarding your levels of body fat.
Of course, with simplicity does come flaws but when it comes to a calculation that can be done in the comfort of your own home, it doesn’t get much better.
Some studies have also shown that ‘overweight’ to ‘obese’ BMI scores can be linked to health-related issues in later life, so it might not be entirely inaccurate.
BMI should not be taken as gospel, and it is necessary to apply common sense to the outcome that it gives you.
This is not to say don’t use the equation at all, it can be helpful, but keep in mind that it is not a universally accurate indicator when it comes to health.