Calculating someone’s BMI is the most common way to find out if they are a healthy weight, but a doctor has slammed the tool. Dr. Karan Raj, a UK-based NHS surgeon, claims the calculator “should not be used” as an isolated tool to predict health risks. What is Body Mass Index?Body Mass Index (BMI) is a widely used medical method to measure if someone is a healthy weight for their height. It’s calculated by dividing an adult’s weight in kilograms by their height in metres squared, the NHS explains. The resulting number determines whether you are underweight, healthy weight, overweight or obese:…