Cat Meffan

BMI: Bullshit Measurement for Idiots

This weekend, my boyfriend noticed on the Guardian homepage, a little box asking readers ‘How Healthy Are You?’, and asking them to calculate their BMI. This stands for “Body Mass Index” and is supposed to tell you whether or not you’re a healthy weight. Go to just about any doctor for a general check up and they’ll do a load of tests, one of which is likely to be BMI, but why do we use it? To be quite honest, with you, it’s all a load of s**t. The BMI number is calculated from your height and your weight, so it sounds pretty scientific and useful – right? Wrong.

Ridiculous? YES. Obese? NO.

Ridiculously cheesy? YES. Obese? NO.

According to BMI, good old Arnie was obese in his prime, as is David Haye?! Look at the their muscles – most definitely NOT obese. In fact, they both have very low levels of body fat. What BMI doesn’t take into consideration is the ratio of body fat to muscle – muscle is more dense than fat, so if you have more than an average amount of muscle, you are likely going to weigh more than average too, therefore pushing up your BMI.

Can you 'pinch an inch'? I doubt it.

Can you ‘pinch an inch’? I doubt it.

So what numbers or calculations should we use?

The answer is simple; none whatsoever. When it comes to how you look and how healthy you are, I don’t think numbers are particularly useful. Yes, you need to get your bodyfat percentage to a relatively low level to be healthy, but it’s far easier to tell that you have a good body fat level by using pictures and the mirror. Take pictures in the same conditions (lighting, time of day, etc.) once every two to four weeks and they will be a far more useful guide.

Apologies for the swearing!