There was a debate a decade ago about the validity of some BMI testing. BMI stands for Body Mass Index and is the most common means used to determine whether an adult is a healthy weight for their height and also the success of diet and exercise regimes. To calculate your BMI you need to know your height in metres and your weight in kilograms. Take these two figures and divide weight by height. Then divide the result by your height in metres again.
The problem that arose a few years ago was the fact that athletes who have very little body fat or people who carry a lot of muscle can have a BMI, which would suggest that they are underweight or obese, even though they are much healthier than people falling into the ‘ideal’ weight category. Certain organisations such as the American military and the British Police Forces had to amend the restrictions placed on applicants to include these exceptions to what was regarded as an ideal BMI.
Now once again the BMI system of determining a ‘healthy’ weight has come under criticism but this time in regard to children. A survey, which has just been published, has shown that BMI is misleading when used as a measure of the success of the Government’s exercise targets. Researchers compared an individual child’s BMI measurement to their amount of daily exercise, by using devices called accelerometers, but were not able to determine a definite relationship between the two results in any of the children. Some of the children who exceeded the recommended daily amount of exercise and were therefore labelled ‘fit’ were overweight using BMI. The results showed that a child can be ‘fit and fat’ as well as being an appropriate BMI and unfit. It is suggested in the report that the only definite way to discover the benefits of exercise in these children would be a blood test.
The study was carried out in Peninsula Medical School in Plymouth and looked at the exercise levels of 113 boys and 99 girls born in 1995 and 1996 over a four-year period.