Put away the scales and BMI trackers, a simple piece of string could tell us how fat we are.
A new study's warning people who are obese may not know it because of the over-use of body mass index tests.
Researchers say it could mean those with a lot of fat around the waist but a low BMI could be unaware they're overweight.
Doctor Margaret Ashwell says there's a simple way to test your size;
