Why Your BMI Is a Useless Metric (Especially for Over 60s)

So, you’ve heard of BMI readings before, likely got your BMI score previously, and your doctor probably swears by it.

‍

However today, I want to let you in on a secret...

‍

''BMI' readings are a useless way for tracking your health and how well you're ageing each year (despite its high use by GP’s and the NHS).

‍

There are several reasons why this is, but today I am going to give you the top 3, (and the third one is going to shock you!)

‍

I'll also share with you a quicker, more accurate (and completely free) way to track it instead!

‍

So let's dive in!

‍

First things first. What does BMI mean?

‍

BMI is a widely used measure to classify us into categories such as underweight, normal weight, overweight, and obese based on our weight and height. Despite its high use by GP’s and the NHS, BMI is pretty useless when it comes to giving us a clear picture of our own health.

‍

Why?

‍

Because BMI stands for Body ‘Mass’ Index. But 'mass' can be made up of several different things, including both fat, and muscle. So what does this really tell us?

‍

The first main problem with this is muscle is denser and weighs more than fat, so a person with a high muscle mass (like an athlete) might have a high 'BMI' and be classified as overweight or obese, even though he has a low body fat percentage and is in excellent health.

‍

Secondly..

‍

BMI ignores the distribution of fat...

‍

BMI does not provide information about where fat is distributed on the body. Visceral fat (fat around the organs) is more harmful and associated with higher risks of cardiovascular disease, diabetes, and other health problems compared to surface level fat under the skin).

‍

That means two people with the same BMI can have very different health risks depending on where that fat is stored.

‍

Thirdly, and the most importantly for us...

‍

BMI does not account for changes in body composition as you age...

‍

As we get older a cascade of things happen.

‍

Our muscle mass and bone density reduce, our hormones change, our testosterone levels drop, and our metabolism slows, leading to many issues including easier body fat gain.

‍

In fact over the age of 60% you’re set to lose upto 3% of your muscle mass each year and 2% of your bone density each year, whilst also gaining weight more easily.

‍

What this means is that your body composition is changing, and not in a good way.

‍

Everything that you need to keep (like muscle and bone) is going down, and everything you don’t want more of (like body fat) is going up!

‍

This means that it is very likely as we age we can be losing strength at 3% per year, gaining weight at 3% per year...

‍

...and in this exact scenario your BMI reading would stay exactly the same and be deemed 'healthy’ whilst the ratio of your muscle to body fat is changing for the worse.

‍

Crazy right?

‍

And this exact scenario is happening to thousands of people around us, including my mum.

‍

The BMI metric was built to be able to categorise a large amount of people in our nation quickly.

‍

We have quick 10 minute GP slots, rushed hospital appointments, long waiting lists, and no time to look deeper beneath the surface.

‍

The system needs need quick and generic testing to cater for all of us.

‍

But whilst that’s a benefit for the system, individually its a problem for us.

‍

We need more than that. And you deserve more than that too

‍

There are of course better alternatives, such as getting your body fat levels taken, or getting Dexa scans. But for the most of us, these are not easily accessible options.

‍

So if that includes you, then here’s 2 key things you need to do:

‍

The first is to complete regular strength training.

‍

It doesn’t need to be hard, or long, in fact 60 minutes per week is all that you need to maintain your muscle mass as you age. But just like brushing your teeth, you need to do it consistently

‍

The second is to ensure your waist measurement is the correct size, and does not increase in size as time goes on. This will ensure our food quantity is altered as your metabolism changes.

‍

Both of these things will mean that even if you get a BMI reading from your doctor, you’ll know that the ‘weight’ and ‘mass’ that he is referring to, is made up of the right things.

‍

Remember it is not the weight that fully matters, it is the ratio of what that weight is made up of that really counts!

‍

Stay strong,

‍

Rob

‍

Founder & Head of Programme

‍

Goodnick