BMI works fine for people who aren't very muscular, which is the great majority of people. Waist to height ratio might be more informative for people with higher muscle mass.
I'm 5'8" and weigh on average 210lbs. My BMI isn't even morbidly obese, it is 31, which is just "regular" obese, but on top of that, a DEXA scan shows that I am actually only 25% body fat, with only 1lb of visceral fat.
Doctor's don't care about that, they see on the Epic chart that my BMI is > 30 and have to tell me some spiel about a healthier lifestyle so they check check off a checkbox and continue to the next screen.
Literally all of them?
Almost every single start of every single appointment (including a follow up from just a couple days prior), they comment about my BMI. It is the rare time they don't that I remember. My last urology appointment the doctor was very congenial, didn't even go over the lab work, just said, everything is looking good, asked how I was feeling, everything good, alright, refilled my prescriptions and left.
Follow that rule next time you read such a statement in a context that's not formal math.
That is not even true. We are talking anecdotal evidence here.
And a near universal experience with doctors for anybody paying attention is that.
One can reject it or accept it and improve upon it after checking its predictive power, or they can pause their thinking and wait for some authority to give them the official numbers on that.
All humans?
Sorry :)
Though, on second thought: yes, all humans, and not merely as a generalization. 100% of humans do it.
On top of that, I'm not sure if that is a real indication of anything, either.
The reason to do that is to get an idea of your abdominal fat (which is the more dangerous place for fat to store), but there are two types of abdominal fat, one is dangerous (visceral fat) and one is completely benign (subcutaneous fat). And a measurement around your waist won't tell you which you have.
I personally have almost all of my fat subcutaneous, with only 1lb of visceral fat (which is right in the perfect range).
It's really hard to tell with the data provided.
Somehow my body is just amazing at working without any help from me. I don't even exercise much. Maybe a few pushups a day, up and down my stairs at my house a couple dozen times a day, and probably 5-10k steps a day max.
Ideal body fat percentage is 18-24% - I'm at 25% (or was in November - might be +/- 2% since then - gained a few pounds weight, but not waist size).
So I would say I'm not morbidly obese or even regular obese based on the percentage of my body that is muscle vs fat.
You would consider incorrectly then.
This person has ~155 pounds of lean body mass. 164 would put him at roughly a body builder level of fat, which basically requires a part time job in cooking and nutrition to maintain.
For reference, I’m in a similar situation to this person. I’m 5’11” (180cm) and about 200 lbs (91kg) with about 170 lbs of lean body mass. My dexa scan says that I’m 15% body fat, but I get the same lectures from doctors about being obese and needing a lifestyle change, all based on BMI and (I assume) my size (I’m barrel chested). It’s completely absurd.
BMI is definitely inaccurate for those with greater amounts of muscle mass, but not as inaccurate as many would like to believe.
The next steps at the doctor is that I show them my MyFitnessPal nutrition tracking, my dexascan, and (at some point) take off my shirt. I ask them what exactly it is I should change. 100% of the time the answer has been something like “Oh, sorry. Please continue as you are doing.”
They just aren’t used to seeing muscular 200 pound dudes at my height in my area at my age (btw, I’m in my 50s).
Also, someone can workout in the gym all they want, but I think most people will struggle with lowering their body fat percentage if they don’t focus on their nutrition.
I realize that my lean body mass (both bones and muscle) are decreasing, and that rate of decrease be higher each year. That said, I’m doing what I can to maintain whatever muscle and bone mass I have.
> Waist to height ratio
Again, while not a bad metric per se, translates poorly between cohorts.
An individual learns nothing from its calculation and it has no clinical value. I receive more constructive feedback from an auntie jabbing me in the chest and saying "you got fat".
> the great majority of people
There is wide morphological variety across human populations, so, no.
When people say "oh BMI isn't accurate" it means you are more overweight then it suggests unless you are literally an extreme body builder.