London: The formula currently used to calculate the body mass index (BMI) is flawed and renders tall people too fat and short people too thin, researchers at Oxford University has said.
BMI is presently calculated simply by dividing a person`s weight by their height to give a rough estimate of amount of fat they are carrying as a percentage.
But Oxford researchers argued that it does not take into account the fact that people`s weight tends to grow with their height to the power of 2.5 giving taller people more room to expand, the Daily Mail reported.
Lead researcher Professor Nick Trefethen told the Times that BMI divides the weight by too large a number for short people and by too small a number for tall people.
Because of this short people are misled into thinking that they are thinner than they are and tall people people are misled into thinking they are fat ter, he stated.
Their proposed changes to the official BMI suggest a strapping person of 6ft 2ins tall would now need to hit 14st 10lb as opposed to just 13st 13lb to be classified as overweight and a hefty 17st 9lb as opposed to 16st 10lb to be obese.
But those standing 5ft tall would now be classified as overweight at just 8st 10lb compared to the old limit of 9st 3lb and would be obese at 10st 6lb compared to 11st.