Let's say that you're 5 feet 10 inches tall and 13 stone 8 pounds in weight... This is a weight you've grown accustomed to and it may not seem so heavy relative to many people around you.
Try putting your height and weight into the NHS
calculator. You're overweight.
Now try inputting different weights until you reach exactly halfway in
the healthy range... It will be around 10 stone 8 pounds. The conclusion -
you're 3 stone overweight.
We get used to being a certain weight and even though BMI isn't perfect, it is a
useful guide. Unless you're a body builder (or very short) it's worth using.