Andy Hawthorne

Why BMI is hopeless

Body Mass Index (BMI) is the tool still used to tell you how fat you are. It shouldn't be, here's why...

Your Body Mass Index (BMI) will scare the bejaysus out of you when it's a big number.

You're overweight and that means you are 10x more likely to die of some horrible condition. 

You'll be diabetic and bits will start falling off. And loads of other cheerful news. 


Okay, so listen to this.

I'm obese according to my BMI. I'm 54 years old, 6 feet 2 inches tall and I weigh 18.5 stone. 

So yeah, I'm obese.

Still hmm...

Because I run 40-60 miles a week, I work out every day and I have a resting heart rate of 46-48 beats per minute. 

A pulmonary embolism did it's best to do me in back in March. The NHS consultant that treated me told me my fitness saved my life. 

Brill, but I'm still obese - or so it seems.

NHS Advice

Here's a line from the NHS website:

The BMI can't tell the difference between excess fat, muscle, or bone.

And then there is this:

very muscular adults and athletes may be classed "overweight" or "obese" even though their body fat is low

In other words, BMI is a guideline for weight - not a rule.

Which is why I argue that beating people with the BMI stick is counterproductive. 

You know when you are overweight

Many years ago I smoked cigarettes. If you asked me whether they were good for me or not, I wouldn't have said "yes".

I never met a smoker who thought cigarettes were good for them. 

Yet people still smoke - because it's an addiction. 

Likewise, I doubt you'd meet many overweight people who thought they were slim and healthy. Not if they were being honest. 

I knew I was overweight. So much so that it used to get me down quite a bit.

Having a doctor tell me I was obese did wonders for my self confidence. But not only that, it didn't help in a practical sense.

The doctor wasn't forthcoming with a plan to help me lose weight. He should have said: "Well, Fatty, you are obese, so bugger off and do something about it."  Because that's the way I received his message.

We need data

What's needed is data. Not some magical number that sounds scientific(BMI). 

Fine, your BMI indicates you are obese. But:

Without knowing the full picture, BMI is not useful on an individual level. 

Move your butt

Encouraging people to move is the best plan. That's what I think. Instead of issuing dire warnings and threatening people, why not explain it in a clear way?

Dumbing the message down is not what I'm suggesting. Making it easy to do is the answer. People have busy lives, health and fitness is not always the top item on the agenda.

Asking people to move more so they can keep doing so when they're older makes more sense.

You are not making it a big deal. 

If you want to still enjoy life when you retire, move your butt as much as possible now.

Simplify the message and it'll get results.