Why BMI Is A Poor Indicator Of Your Health – And How To Do Better

Today, you might have seen that we announced a new app on the App Store, called Fitness Meter. The premise for the app is that the Body Mass Index, or BMI, is a poor indicator of your health and fitness.  We thought it might be useful to give a concrete example of how our app can do a superior job of assessing someone’s fitness.

This is a real example of a male who was told by his doctor that he had to lose weight, because his BMI was too high.  Here’s the story of Phil D. (taken from a comment the excellent science-based blog, Obesity Panacea – see the comment on this article about BMI for the original comment). Phil D, wrote,

I am 6’2 (1.87m) and weigh 216 lb (98 kg)  [Ed - Phil wrote he weighs 116lb, but this was a typo - he meant 216lb, which is 98kg]
I have a 36 inch (91.5 cm) waist and a 44 inch (112 cm) chest
I am 53 years old and run about 10 miles (16km) per week and push a few weights to stay in shape I have moderate 16 inch (40cm) biceps and have a nascent six pack, which you can see through the layer of fat when I tense my muscles.
My cholesterol is 5,0 mml and my blood pressure is 120/80.
I think I am doing fine,
But… apparently, I have a BMI of 28.2 and am overweight, nearer obese than normal.
According to the figures, I need to lose 22 lb (10kg) yes 22 POUNDS, before I can be classed as normal.
I am no Arnold Schwarzenegger, but I am definitely NOT obese, nor even overweight.
10 years ago I actually achieved my top end acceptable BMI when I was very ill, and that is exactly what I looked like… VERY ILL.
Recently my new doctor told me my BMI is too high and I should lose weight. When I protested he actually LOOKED at me and said, well you do seem to have a lot of muscle, maybe you can carry a bit more weight.
Either BMI is relevant or it isn’t! My ex-wife is in the bottom end of the BMI limit, but she is CLEARLY emaciated and lacking in energy.
Doctors! Please, I EMPLORE you stop believing in arbitrary numbers and limits and treat the person in front of you.
BMI may work for the statistically normal, but two minutes examination will tell you much more than 2 minutes calculation.
STOP treating us by NUMBERS!!!!

Now, fortunately, for Phil, he knew what he would look like if he had taken his doctor’s advice, because he’s been that weight previously. So he protested his Doctor’s diagnosis.  His doctor decided to do a proper examination rather than blindly diagnose his patient’s condition using BMI. The doctor accepted that Phil wasn’t overweight.

So, how does Fitness Meter do with Phil’s case?  First, we plugged his numbers into Fitness Meter – they look like this:

Then we did two things. First, the Artificial Intelligence (AI) based assessment of his current condition. Second we used the AI model of weight loss and weight gain in the app to estimate how much weight he’d have to gain to become marginally overweight.  In the screen shot below, the green needle shows his current condition, and the yellow needle shows how much weight he’d need to gain to become overweight from a health point of view.

As you can see, Fitness Meter assessed Phil’s current condition as “Healthy Weight”.  Not only is he in the Healthy Weight category, but you can see from the graphical display (look at the green needle on the display), that he’s well into the healthy range. As he said himself, he’s no Arnold Schwarzenegger, which suggests the app assessed him correctly (the other categories in the Healthy Range are “Fit” and “Athletic” – both of which represent conditions that are fitter than the Health Weight category). Whereas, the BMI-based diagnosis put him as significantly overweight, and nearer obese than healthy.  The Fitness Meter computer model of weight gain suggests that far from being overweight, Phil would have to gain another 27lb to become “Marginally Overweight” (the yellow needle on the display).

So, there you have it – a real world example of how you can do better than BMI if you’re looking to assess the state of your health and fitness.

 

 

 

Announcing Fitness Meter For iPhone

A New Approach To Helping You Get In Better Shape

Unique technology based on the latest healthcare and medical research

Today, we’re pleased to announce the immediate world-wide availability of a new app for iPhone called Fitness Meter.  Fitness Meter represents a new approach to helping people get into better shape. It incorporates unique technology that we’ve developed based on the latest international healthcare and medical research.

If you’re looking to get in better physical shape or lose weight, the unique new software technology in Fitness Meter helps you quickly and easily understand exactly what you need to do to achieve your goals. The secret to getting in better shape is to assess your current physical condition accurately; and then make sure you get the right nutrition, and do enough exercise, to make progress.

The starting premise for Fitness Meter was that it’s actually surprisingly difficult for people to understand what kind of shape they’re really in.  There are a few reasons for this, one of which is that almost everyone, from individuals through to healthcare professionals, uses a measure called BMI (Body Mass Index) to assess or diagnose physical condition. The problem is – BMI simply doesn’t work effectively as a diagnosis tool for individuals. Indeed, it was never supposed to be used like this.  The reason it’s become so widely used is simply because it’s trivial to calculate. The  Wikipedia article on BMI explains the situation well:

BMI was explicitly cited by Keys (the person responsible popularising BMI) as being appropriate for population studies, and inappropriate for individual diagnosis. Nevertheless, due to its simplicity, it came to be widely used for individual diagnosis, despite its inappropriateness.

So why doesn’t BMI work?  That reason is that it’s a measure of weight, not of body composition, and certainly not a measure of body fat. In other words, BMI  doesn’t account for muscle and fat in the human body.  So, someone in great physical shape with lots of healthy muscle, would be diagnosed as being overweight or even obese when judged by their BMI. That makes it unsuitable for assessing the condition of an individual person.  Now, to many people, this won’t come as a surprise. Increasingly, it’s becoming common knowledge that BMI isn’t up to the job that people are using it for. We thought we could do much better by using more advanced software technology.

Fitness Meter is based around a new computer model of the human body that takes into account muscle and two types of fat (healthy and unhealthy); and AI (artificial intelligence) technology, The app provides you with a genuinely personalized assessment of the current state of your body from just a few simple pieces of information. You’ll be assigned to one of ten categories ranging from Dangerously Underweight; through Athletic, Fit and Healthy; up to Morbidly Obese.  On the graphical display, you can see your current condition in the context of all possible conditions. For example, if you’re a little overweight, you can see visually just how far you are from achieving a health weight. Having assessed your current condition, you can simply and interactively explore your health and fitness goals.

One of the big benefits of this technology is that having an accurate assessment of your current physical conditions enables you to make much better choices about your goals. As the app lets you explore possible goals it’s also able to show you precisely what you need to do achieve them in terms of nutrition and exercise; and show you how long it will take to reach them.  It gives you all the information you need to decide on what you feel is achievable for you.

Dr Simon Brocklehurst, CEO of Psynixis, said,

There are so many problems using BMI to assess people. Aside from the fundamental issues of it not being an appropriate tool to use for diagnosis, many healthcare professionals aren’t fully acquainted with what it really means and what the limitations are. To consumers, BMI can be incredibly confusing – often people don’t know what the number is supposed to mean, let alone what it actually means. There’s a need for people to be able to assess their physical condition in a more accurate way, and also in a way that’s easy to understand. We hope that Fitness Meter really helps people to properly understand what shape they’re in and to set themselves goals that they’re motivated to achieve. To help with motivation, there are options built right into the app for Tweets that let you quickly share your goals and your progress with friends.

So, what exactly IS your physical condition right now? What about your goals? Maybe you’re looking to get healthier? Or maybe you’re already healthy, but want to get really fit to look your best. How MUCH should you be eating? How MUCH exercise do you need to do? Fitness Meter gives you precise answers.

We’ve designed the app to be super-easy and quick to use, so if you want to update your data every day to check your progress towards your goal, it will only take a second. You won’t find the technology in Fitness Meter anywhere else, it’s exclusive to iPhone. For more information, please follow these links:

Follow Psynixis on Twitter @Psynixis, and follow Fitness Meter @FitnessMeter.

For more information, contact:

Dr Simon Brocklehurst
info@psynixis.com

Notes For Editors

About Psynixis

Psynixis is a privately held software start-up based in Cambridge, UK, one of Europe’s primary centers of excellence for cutting-edge software and healthcare. The company designs and develops advanced software for iPhone and iPad aimed at global audiences. It has world-class expertise in a number of areas, including healthcare, which is the focus of the app, Fitness Meter, available on the App Store.  The company has active R&D programs in software for healthcare, photography, and mass transit.