Alternatives To BMI For Checking Your Health
Check-ups at the doctor's surgery, pre- summer/ post Christmas panics and health-focussed magazines frequently crack out the Body Mass Index (BMI) to check whether we are healthy, overweight or obese, but some experts question whether it's the best way. If it were then Jonny Wilkinson (phwoor) and Brad Pitt in Fight Club (excuse me for a moment) would be classed as overweight.
So if BMI measurements don't report back on your health properly, what should we use instead?
How to measure your BMI
The measurement was created 150 years ago by Adolphe Quetelet and compares to our height to our weight. You simply divide weight (kg) by height (m) or use this BMI calculator.
Alternative 1: common sense
Are there new wobbly bits attached to your bottom? Are you out of breath and unfit? Then you are probably overweight. If your dress size is going the wrong way and you don't exercise, then common sense tells you that a healthy weight is slipping from your grasp if it hasn't already gone flying across the room.
Alternative 2: ABSI
Scientists have a new way of measuring body fat. Step in the A Body Shape Index (ABSI), developed by the City College of New York.
It's similar to the BMI formula but adds in a waist measurement to account for fat. ABSI is too complicated to figure out on your own, even the scientist use a computer program to concoct the outcome and your chances of dying from weight problems. A recent study in the PLOS ONE medical journal found it was 'highly accurate' at predicting deaths.
Alternative 3: BAI
There's also the Body Adiposity Index. It was developed by the University of Southern California and divides height by hip circumference to calculate body fat. Scores under 23 are healthy but 23-29 is overweight.
The results can be very different from a BMI reading. For example, a woman who is 5'1 and weighs 9 stone comes out with a healthy BMI of 23.8. But if she has a hip measurement of 39" - making her a dress size 12 - the BAI result is 33.1% and she is classed as having too high a body fat percentage.
Scientists believe this is a better measurement as it takes fat distribution into account.
Richard N. Bergman, Keck Professor of Medicine at the University of California's Keck School of Medicine, said "you get a number which is the percent fat". This measurement may be easier to understand than BMI, as there are clear guidelines for health body fat percentages for men and women.
Alternative 4: waist measurements
NHS doctors tend to keep it simpler. Neither of the new measurement systems is used by the NHS.
Dr Haslam, Chairman of the National Obesity Forum, says "I use waist circumference as a measure because it's manageable. If you have a big tummy you need weight management".
The maximum tummy measurements as suggested by Diabetes UK are:
- Women 31.5inches
- White or black men 37 inches
- South Asian men 35 inches
The smaller measurement for South Asian men is due to their propensity to deposit belly fat easily.
Why is this important?
Measurements of weight and health are important because visceral fat - that's the extra stuff - is thought to be a risk factor for diabetes and heart disease, the biggest UK killers and a real problem worldwide. BMI is flawed because it only takes into account height and weight - so even top class athletes can be 'obese'.
Dr Haslam suggests tummy size is the main indicator of an unhealthy weight, so get your tape measure out and put down those M&Ms in exchange for a brisk walk and an evening of Fight Club for inspiration.