Remember that the BMI is a very crude measure that completely ignores your build and boobs. A woman may be easily carrying 5 lbs of breast tissue. Beyond that, the size of your bones matters too. Some armed services use a frame size indicator to determine what is a healthy weight. This involved measuring the wrist to determine bone size.
Here is an example:http://www.military.com/join-armed-forces/coast-guard-weight-rules.html
You can see that there is a big difference between what could be a healthy weight for the women with bird bones and those with dino bones.
And this doesn't even get into differences in muscle mass. People who lift a lot of weight will often put on significant muscle mass without adding fat, which can push up their BMI.
Here is an example:http://www.military.com/join-armed-forces/coast-guard-weight-rules.html
You can see that there is a big difference between what could be a healthy weight for the women with bird bones and those with dino bones.
And this doesn't even get into differences in muscle mass. People who lift a lot of weight will often put on significant muscle mass without adding fat, which can push up their BMI.