Comment by arcticbull | Hacker News Reader

Comment by arcticbull | Hacker News Reader

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While that joke is accurate (although some football players are also obese [1] depending on their position -- Aaron Gibson was 400lbs), BMI was never meant to be applied to individuals. It was designed to be applied to populations. It does a good job of that. Also note that guidelines have historically been created against a very limited selection of race and have not appropriately adjusted for height (although BMI 2.0 corrects the height issues).

If we're just relying on the professional's opinion then they don't really need the BMI, right. They can just look at you and go "huh, you're looking a little thicc today."

BMI is a good tool for population health, a bad tool for individual health, and if it just so happens to correlate to your thiccness then you probably already know that.

I agree with parent that body composition analysis via DEXA or air displacement plethysmography is a far better metric.

I have no doubt that a carpenter can bang a nail in with a screwdriver 90% of the time, that's why they're professionals after all, but when I see it, I can't help but think "there's gotta be a better way mate."

[1] https://www.nytimes.com/2019/01/17/sports/football/the-nfls-...

Why would race matter?

Melanin doesn't effect fat comp... does it?

Body composition varies by race.

https://pmc.ncbi.nlm.nih.gov/articles/PMC4968570/

https://www.sciencedirect.com/science/article/pii/S000291652...

They don't need to be causally connected, just be correlated.

> Why would race matter?

Because social matter

It's really not, and it's always weird when people jump to that conclusion.

Different genetics lead to different health outcomes for the same body fat percentages - or the same BMI on a population level. Just as it's not a "social matter" that the prevalence of sickle cell is much higher in African Americans. It doesn't make sense to use health outcomes standardized against a BMI range for one population racial mix against individuals of a race not represented -- in at least two separate ways.

Hong Kong for instance sets the obesity cutoff at a BMI of 25. China and Singapore use 27.5 I believe. The WHO and various other organizations generally endorse lower cut-offs for people of Asian descent. [1]

[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC10108164

Sickle cell isn’t affected by social matters, unlike body fat.

I'm not sure if you're following what I am saying. The same body fat percentage leads to different health outcomes for members of different races in aggregate because of different genetic predispositions. Someone of one race with BMI X is likely to have a different risk profile than someone of a different race with BMI X no matter what X is, high or low. This is not a social matter. We're just talking about heath statistics, not aesthetics.

That's not to say there aren't social aspects to obesity as well (obviously) but that's not what we're talking about right now, and parent dragging that in is just a distraction.

From [1] in the comment you replied:

> Access to medications and surgery should be improved, in part by updating US indications for therapies to reflect race‐specific obesity thresholds and through inclusion of Asian American people of all subtypes with lower BMI values in clinical trials.

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