The Body Mass Index formula created by scientists to calculate if someone is overweight traditionally divided the person’s weight in kilograms by their height in metres squared, with the aim of giving the individual a measure of their body’s fat level.

However, scientists are arguing that the chart has made tall people more overweight and those who are shorter not fat enough as it did not take into account a person’s weight tends to grow with their height, giving taller people more room to bulge.

Professor Nick Trefethen, a leading mathematician, has said: “The NHS relies on the BMI pervasively in all of its public discussions of obesity.  We deserve an explanation of what justification they have for using this formula.  BMI divides the weight by too large a number for short people and too small a number for tall people.  So short people are misled into thinking they are thinner than they are, and tall people are misled into thinking they are fatter.”