Is BMI still a relevant measure of health?

 

BMI is an easy and consistent general measure of health that has been used extensively over the years, because it requires:

  • 1 variable, weight (kg),
  • 1 piece of equipment, a reliable set of scales

 

A high BMI (>25kg/m2) has consistently shown to be an increased risk factor for chronic diseases such as :

  • Heart and blood vessel disease
  • High blood pressure (hypertension)
  • Type 2 diabetes
  • Osteoarthritis, especially in the hips and knees
  • Certain types of cancer, such as colon and breast cancer
  • Depression and other mental health disorders
  • Gallbladder disease

 

BMI is a good measure of general body composition, but falls down in the 2 following main scenarios:

  • Overestimated body fat for large framed men OR trained individuals with a low body fat percentage. The average body fat percentage for
    • Women are 25-31%
    • Men are 21-24%,

However, excellent amounts are:

    • Women are 18-24%
    • Men are 14-20%

 

Muscle mass is denser than body fat and, as a result, BMI overestimates the health risk for such individuals. It doesn’t take into account the health benefits of the higher muscle mass, such as improved glucose control and improved overall body strength.  However, measuring body composition requires sophisticated equipment. Equipment such as a DEXA scan or using equations to estimate composition using body fold measurements, which, has its own set of errors.  In general, using body fat percentage is a more important measure of health, but be aware, it also has errors.

 

The best approach would be to use body fat % measurements but understanding there will be errors. However, we can measure the change over time to really see if you are making progress.

 

Finally, a very simple and reliable measure of health is waist circumference. This only requires a tape measure.

 

Abdominal fat (belly fat) is consistent and correlates well with increased disease risk for chronic diseases, such as heart disease and diabetes.

 

A good number for waist circumference is:

    • Women <80cm
    • Men are <94cm

High numbers are considered:

    • Women: 81-88cm is an increased risk,  88+cm is a substantially high risk
    • Men: 94-102cm is an increased risk,  102+cm is a substantially high risk
 
 

 

 

 

Want to know more?

If you would like more information or have any questions about the importance of glute strength and how exercise can help improve this please comment below!

Or are you a new client and would like to book for a FREE full body assessment with one of our Physiotherapists or Exercise Physiologists? Book online, call us on 03 9857 0644 (Kew East), 03 9842 6696 (Doncaster East) or send us an email at admin@mdhealth.com.au

Author: Michael Dermansky

Michael has now been working in physiotherapy for over 20 years, since graduating from Melbourne University in 1998 and is even more passionate about getting the best outcomes for clients than he was then. Michael is always studying and looking for new and innovative ways to improve the service at MD Health, including and not limited to the ideas from the fitness industry and great customer service companies. In his spare moments, he loves spending time with his two children, Sebastian and Alexander and hopefully taking them skiing more and more often.

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