According to the NHS, I’m overweight!

As soon as i entered the room the nurse started asking me questions; How tall are you? Do you exercise? Do you smoke? Do you drink?

I guess the usual things asked when evaluating someone’s general health condition.

“1.88 meters, I exercise almost everyday, I don’t drink and I don’t smoke.” I answered.

I gave her accurate information about my lifestyle. That, together with a visual assessment must have already told her a lot about my general health.

We measured my blood pressure, it was a little low but that’s not unusual for an early morning appointment. All good, another health box ticked.

I was then told to step on the scale. 90 kilograms with all my clothes on sounded about right.

The nurse went back to her desk and entered all my stats into the computer. She looked at me and stated, “You’re overweight.”

I looked at her, smiled and asked, “Am I?”

“Yes, you’re 1.88 m and 90 kg. That’s slightly overweight.”

“Do you mean BMI?” I asked

“Yes, your BMI. Ah, you’ve got lots of muscle, haven’t you?

“Yes”, I nodded and smiled at her again.

So, why the confusion? Let me explain. 


Body Mass Index

Everyone has heard of BMI – weight in kilograms divided by height in meters squared. The established criteria for BMI is: underweight <18.5 kg/m2, normal weight 18.5 -24.9 kg/m2 and overweight 25 – 29.9 kg/m2, or obese >30kg/m2.

My BMI was over 25 kg/m2. So technically, according to this method I really am overweight.

Does this look like I’m overweight? 


But I’m not overweight. I exercise a lot and am therefore heavier than an average person who’s my height but doesn’t lift weights and doesn’t have as much muscle mass as I do.

Now, I’m not massive, I’m not Arnold Schwarzenegger or Dwayne ‘The Rock’ Johnson. Imagine how “overweight” they must be, if I already fall into this category.

How useful is BMI anyways? Does it tell us a lot about our health?

BMI wasn’t created to differentiate between Conan and the Michelin Man.

It’s true that BMI classifies muscly people as overweight. Why? Because BMI measures relative weight, fat mass and muscle mass are not taken into account.

However inaccurate in some cases it might be, BMI will apply to the large majority of the general population. There are not many people who fall into the overweight or obese range and look like Dwayne Rock or Arnold Schwarzenegger.

It’s fairly easy for almost everyone to tell whether someone’s excess weight is due to their fat belly or their massive, ripped body.

BMI is being used as an indicator for health. Does it really tell us much about someones health? Here are some problems with this method of measurement:

It misses normal weight obesity

It doesn’t measure your body fat. Some people seem to have normal weight for their height, however they have too high body fat percentage (>30% women and >20% men) which classifies them as “normal weight obesity”. These people may look thin but they are exposed to the same health risks as clearly overweight people.

It doesn’t change in response to exercise

BMI may not react to changes in your exercise routine and diet, especially if it’s not a calorie restricted diet. More exercise and better choices in your diet won’t change your BMI unless you lose some weight. However both of these changes will potentially make you a healthier person. BMI won’t take this into account.

BMI does’t differentiate between types of fat

Body fat presents different kinds of risk to our health depending on the place of its accumulation. A person with a high BMI, but who carries a lot of fat in the hips and rear is probably not at as serious of a health risk as a person with the same BMI storing most of their fat in the stomach.

Do we need BMI?

Yes. Why? BMI is quite easy to standardise and although it’s an imperfect tool, measuring it doesn’t require any special equipment. It’s an easy rough instrument that helps us to gain a general idea about a person’s health. However it shouldn’t be used as the only way to decide whether someone is obese or overweight. Other factors should be taken into consideration. Don’t be that nurse!