For quite some time now, the government has been preaching Body Mass Index chart as the gauge to determine what a person should weigh based on their height to weight ratio. In recent news, an Oxford mathematician discredits this chart because it gives tall and short people inaccurate readings. Body Mass Index is calculated by using your weight in kilograms divided by your height in meters squared. A normal range of BMI can consist of about 18.5 – 24.9; 25 – 29.9 is overweight; and 30 and above is considered obese.
There are many problems with this chart one of the major ones is that if you have a lot of lean muscle tissue, you can be defined as clinically obese because you weigh more than the recommended amount even though your body fat percentage is low. According to mathematics professor, Nick Trefethen, he says that if your tall you might lose a point or two which could make the difference between obese and overweight or normal and overweight. He suggests that the chart is flawed because it fails to account for the fact that tall people can take up more space without being fat. He says, “We live in a three-dimensional world, yet the BMI is defined as weight divided by height squared,” Trefethen wrote in a letter to the Economist, published January 5. “It was invented in the 1840s, before calculators, when a formula had to be very simple to be usable. As a consequence of this ill-founded definition, millions of short people think they are thinner than they are, and millions of tall people think they are fatter.”
He later clarified on his website, “I don’t believe that 2 should simply be replaced by 3. People don’t scale in a perfectly linear fashion as they grow. I believe a better approximation to the actual sizes and shapes of our bodies would be given by an exponent of 2.5.”
That means the new BMI = 1.3 x weight(kg) / height(m)^2.5 = 5734 x weight(lb)/height(in)^2.5.
He is certainly not the first person to criticize this chart, as a personal trainer I personally never liked this method because it is an inaccurate way of determining one’s health. Yet most school districts are using this as there determining factor to tell whether a child is healthy or not. Obesity in children has sky-rocketed because of the lack of gym in the schools these days. If you combine inactivity with unhealthy lunch choices and parents having to shuffle children on the go with most dinners coming from fast food places, it is no wonder obesity has been on the rise. If you study the research closely the key to healthy children is INCREASING ACTIVITY levels which has been proven to increase grade point average. This seems like a pretty simple solution, yet we would rather embarrass a child using an inaccurate method that the government has promoted along with their illustrious food pyramid. We all know how well and accurate the food pyramid turned out to be. Chalk another win up for the government and our educational system. Hopefully, one day we can fix these problems so we can progress as a society instead of regressing.