Body Mass Index

The Body Mass Index (BMI) is in the news at the moment. I've been looking at my BMI and am distressed to find that I am an inch (2.54cm) shorter than my ideal height. If I could only grow taller by just that tiny bit I would be an "Ideal" 25 rather than an "Overweight" 25.6.

On the other hand, if I was to shrink to 5ft 7in (1.7m) I would then be "Obese", but as that is a loss of 6 inches I am hoping that won't happen.

Even better, I would have to get a severe attack of the "shrinks" to get to be "Very Obese" as I would only be 4ft 10in (1.47m).

At the other end of the scale I do hope giantism doesn't kick in, because if I were to suddenly grow to 7ft 2in (2.18m) I would be officially skinny, or "Underweight".

One fascinating fact though, I am lighter that 70% of Americans of the same sex, age and height though I am not sure how much taller I am than Americans of the same sex, age and BMI as me!

Hmmm.... What does the BMI represent anyway? It is your weight in kilos divided by your height in metres squared.... Well then that means that if you met with an unfortunate accident involving a steam roller that squished you out to so you were as wide as you are tall then the BMI index tells you how much 1 square metre would weigh (in kilos)....

Hang on though - how thick would I be, if I were rolled out square like a piece of pastry?

If we assume the human body has the same density as water (1kg/litre, or 1000kg/cubic metre) then we can work it out. A cube of water 1 metre by 1 metre by 1 metre would weigh 1000 kg, a cube of me 1 metre by 1 metre by x metres thick would be 25.6 kg, so substituting through I would be 0.0256 metres thick if I was rolled out square, or 2.56cm, or almost exactly an inch thick....

Put it another way your BMI is your thickness in millimetres if your were rolled out into a square!