I suppose it's good for a rule of thumb, but it always cracks me up when I use one of these. They are so obviously not intended for anyone with even a moderately athletic build.
At 5'10" and 170lbs, it places me on the cusp of being overweight! For grins, I started going backward to see where the cusp of underweight lay...and found it just under 130lbs! Even when I was a scrawny thing in high school, I was still around 145...I can't imagine dropping back to that size, much less to 130. I'd be skin and bone. And cock. :wink: