Ah, here you see the problem. Skin fold tests are difficult to do ith ant accuracy or reliability. The electronic scales are far from perfect as well. Accurate fat measurement requires water weighing or some other fancy technology that few have access to. Therefore BMI is used as a flawed but accessible stand-in.
This reminded me of something. The Detroit Free Press did the bmi for the detroit red wings. Every one of them qualified as overweight and unhealthy.
That’s my $.02
“Overweight” but not “obese”. “Overweight” was the term used, not “overfat”, because there was a recognition that some would be overweight secondary to an increased muscle mass not fat. “Obese” is where concerns should start.
Not to excessively defend the very flawed BMI approach.
But they openly admit that for athletes with high muscle mass, the BMI is inaccurate. I agree it’s off for athletes, and that the low end of “normal” seems REALLY low. But I also think people exaggerate those problems in the way of denying their own, accurate, BMI reading of obese overweight.
I want to second this because it’s a very important point.
Even hydrostatic weighing carries something like a 3% margin of error. Those scales and other gizmos have much higher error ranges. Skinfold calipers CAN be accurate, but it depends on who is doing it, and how many sites on the body they utilize.
Back when I took exercise physiology in grad school we did a lab demonstrating this. We took everybody’s percent of body fat using different techniques, and the graphs were all over the place. Big, BIG ranges depending on method and measurer.
BONUS QUESTION: What’s the most accurate method of measuring percent of body fat? (Hint: it’s not hydrostatic weighing)
Dissection and a very accurate scale? 
When I graduated high school, my BMI was 16. Yet I was, and still am, healthy. How is that?
Ding ding.
Uh what is a Dexa scan Alex. Wild and wooly for 600.
Bingo!
My prof asked us that one. We all sat there racking our brains, trying to think what was more accurate than hydro weighing until she said, “Autopsy.”
Good egg, because it is a statistical probability valid for populations stating increased or decreased risks NOT what health a particular individual is in. Okay?
thank you for posting for the visually impaired.
I have no idea where this “short” business came from, either. I’m very short and my BMI “normal” range seems about right to me.
Frankly, I think the most reliable indicator of obesity is a snarky attitude when pointing out that atheletes are misrepresented by BMI.
BMI was probably more useful before everyone and his dog had heard about it, because the people who still need to get the message it has to offer are just going to be in denial at this point. So is the BMI STILL useful? I don’t know. But it probably was good a few years ago.
This sentence alone makes me glad I created the thread.