What is it?
Waist circumference is also called waistline. It is the distance around the abdomen measured just above the belly button. It is not trouser waist size!
What is the healthy range?
What is deemed to be a healthy waist circumference varies by body type, sex, and ethnicity. So instead of using just the waist measurement, the waist-to-height ratio provides a more reliable indicator of insulin resistance. The waist-to-height ratio is simply a person’s waist circumference divided by their height.
It is generally accepted that for health a person's waist circumference should be less than half their height. If waist circumference is more than half a person’s height they may have insulin resistance.
Why does it increase with insulin resistance?
Insulin resistance and high blood insulin cause increased fat to build-up inside the belly. This increases waist circumference.