Knowing your waistline to height ratio is a simple screening test to do at home; and it is far more meaningful than knowing your BMI (body mass index). The problem with BMI is that it doesn’t take muscle mass and other important factors into account - one of the most important being exactly where our weight is distributed. Someone with a naturally bigger frame is going to weigh more than someone with a narrower frame, but that doesn't mean the person who takes up more space is automatically healthier than the 'smaller' person.
Conversely, comparing our waist to height ratio provides us with one of the most important health screening tests there is ˗ and it’s really simple, too. It is also important to be aware that the fat we should be most concerned about losing is the fat around our waistline: our visceral fat. This fat provides one of the most accurate predictors of both healthspan and lifespan. Whereas carrying subcutaneous fat (the jiggly fat just under the skin) is normally harmless.
The string test
Even if you don’t have a tape measure, here is a simple test you can do with a piece of string! First take the string and cut the length to your height. Next, while breathing normally wrap the string around your waist at belly button height. If the string will not wrap around twice then, this is an indicator you may have an issue with insulin resistance. The goal is to be able to wrap it around your waist twice. Interestingly, for people who can’t loop the belly twice (more than half of the population), we suggest you don’t do any jogging at all until your belly reduces to half of your height.
If you do have a tape measure, then it’s good to calculate the actual ratio and measure it weekly as you make changes to your diet and lifestyle.
Interestingly, it is widely accepted in medical circles that if your waist to height ratio is less than 0.5 AND you currently have two of the following four conditions: high blood pressure, high triglycerides, low HDL, or high blood sugar, then you currently have metabolic syndrome. Notice how your waist to height ratio is a prerequisite. It’s like the anchor. While this does not mean that people with a slender waistline can’t have metabolic issues, if you do carry excessive weight in the midriff, then it is likely that changing your diet and lifestyle will be beneficial for your inner health.
There has been great research in this area, predominantly in the UK.1 Dr Margaret Ashwell OBE at Oxford Brookes University said of their findings, ‘The use of WHtR [waist to height ratio] in public health screening, with appropriate action, could help add years to life… If health professionals included this simple measurement in their screening procedures, then many years of productive life could be saved.’2
The conclusion of her research stated [info in brackets we have added for clarity]:
‘This systematic review and meta-analysis* is the first to show that WHtR [waist to height ratio] was a better predictor than WC [waist circumference] for diabetes, dyslipidaemia, hypertension and CVD risk in both sexes in populations of various nationalities and ethnic groups. By including data on more than 300,000 individuals from diverse populations across the world, it supports previous suggestions that measures of abdominal obesity provide superior tools for discriminating obesity-related cardiometabolic risk compared with BMI. Moreover, WHtR has better discriminatory power than WC.’
*[a statistical analysis that combines the results of multiple scientific studies]
Without trying to oversimplify what is of course a complex subject, please use this guide as a general rule of thumb:
|Adult Men||Adult Women||Categorisation|
|Less than 0.34||Less than 0.34||Extremely Slim|
|0.35 to 0.42||0.35 to 0.41||Slim|
|0.43 to 0.52||0.42 to 0.48||Healthy|
|0.53 to 0.57||0.49 to 0.53||Overweight|
|0.58 to 0.62||0.54 to 0.57||Very Overweight|
|Over 0.63||Over 0.58||Obese|
If you've done the waist to height ratio test and discovered you're in the 'overweight' or higher category, and you want to do something about it, we recommend checking out our Waist Loss Programme.