Your BMI, body mass index, is a relationship between your height and your weight.

BMI is a very quick and easy way of labeling someone as underweight, healthy or overweight and identifying those that whose health risks may increase.

For anyone looking to join the British Army, your BMI needs to be between 18 and 28...

How can I check my BMI?

There are loads of online calculators available, like this one on the NHS website, or you can use this BMI chart I found on diabetes.co.uk.

Just track two lines with your finger across from your height and up from your weight to find out where you fit.

Is BMI the right way to screen?

The problem with using BMI as a measure, is it's not the be all and end all when it comes to a person's fitness.

Someone who is extremely muscular may have a high BMI, but incredibly fit and the other end of the spectrum, someone that falls in the "healthy" zone may be thin enough for a low BMI, but have terrible fitness.

Take a look at out pin board below. It features professional athletes that would fail British Army Selection because their BMI was too high!

Will my BMI stop me joining the Army?

It can do and it will almost definitely get you medically deferred from selection. In fact, it actually happened to Dylan who was on work experience with us.

There are 1000s of people applying to join every year and the MOD need a way of quickly ruling people out.

Otherwise the whole recruiting process becomes expensive and unmanageable.

Have you successfully appealed a BMI deferment?

We'd love to write a post on how to appeal a BMI deferment decision and need your help.

Have you done it or know someone that has?

If yes, please comment below and share this post with them.