Let’s get moving NHSubmitted by bluesmom913 t3_11fidy2 in newhampshire
deadliftothersup t1_jajt185 wrote
Reply to comment by No_Suggestion_8234 in Let’s get moving NH by bluesmom913
BMI was designed for population health and even blood pressure has plenty of outliers in terms of individual predictive power. Some doctors are lazy, but that's not really the fault of the metric. Anyone doing a competent exam is going to use multiple metrics anyway to assess health.
On that population scale, it's completely fine. The nation is not populated with linebackers and bodybuilders.
Although 6'6' 210lbs doesn't put you at or above 25, the category cut offs are largely arbitrary and it, like blood pressure is better thought of as a dimensional variable anyway.
Edit: because I want this to lean educational. When I've used other quick adiposity measures like waist circumference, waist to hip ratio, they all more or less have limitations on the individual level, but weren't head and shoulders better predictors of long term health compared with BMI.
MindlessHousing t1_jajulet wrote
> BMI was designed for population health
BMI was just observational data collected by a French statistician in Paris in the 18th century. It’s not even remotely scientific
It compares mass to surface area which is absurd since the volume of a shape increases faster than the surface area and mass = density * volume
deadliftothersup t1_jajx3x9 wrote
I've posted links to meta-analyses on BMI as a predictor of various health outcomes. I'm not even coming close to scratching the surface on what is available.
sje46 t1_jam7j9q wrote
Anyone who disagrees with the above comment: yes, it's probably not the most perfect measure, especially for individuals but it's a very quick measure and let me ask you one very important question:
One town has an average BMI of 23.5. Another town has an average BMI of 28.4. In most other ways they're comparable (similar age range, poverty level, etc) Which town do you expect to have a lower death expectancy? Which town will have more health problems overall? What is the quickest way to determine this factor? Looking at average weight alone is also a good indicator, but seeing how different people groups have different average height (especially different sexes), the BMI isn't that much harder to get information for and provides just a little more information.
I don't see the problem with BMI at all. I see much bigger problems with IQ testing (which are culturally biased) and Flesch Kincaid (which is complex, very difficult to measure and ill understood and greatly misinterpreted) and pretty much every psychometric test ever. BMI is a quick and dirty way of determining which places have weight problems.
Rejecting it will just make tracking this stuff harder, less intuitive, and people more likely to embrace a more extreme version of "healthy at every size" which turned from actually pro-active health stuff for overweight people to just apologia for passive unhealthy lifestyles.
See a doctor to determine if you're actually overweight. BMI is fine.
deadliftothersup t1_jamlkrk wrote
Thank you, this more of less boils down the issue. New Hampshire likely doesn't have a meaningful level fewer bodybuilders than say Mississippi in a way you will see on the population level. I get folks' aversion to BMI. Fat shaming has unfortunately only increased despite it being more and more likely to be overweight which has negative impacts and doesn't lead to positive behavioral change on the whole. There is also no need to throw out metrics where they are useful and when we understand the limitations.
Similarly, as a person that used to be in cognitive performance research, it's both fine to be skeptical of individual results and realize that these tests are very useful for studying cognitive decline over time.
-cochise t1_jan1nyr wrote
IQ tests predict health outcomes too though. They’re not really culturally biased any more.
No_Suggestion_8234 t1_jaju15x wrote
And you have a source for any of this?
deadliftothersup t1_jajwth4 wrote
Sure, I'll start with a basic muticohort mulitcountry study but it is one of the most used health metrics in population health, so I could dog up thousands depending on what you specifically want to know.
Here is a meta-analysis of 143 studies on mortality. Notice that there is a relatively wide range of where folks are not passing early, but in general, the higher the more problematic. Now if we are talking joint health, the point at which BMI is a predictor of pain is likely a lot lower than mortality for most folks.
I'd be happy to talk about the limitations of BMI as well. I've published papers on issues of self-report as well as the the bidirectional nature of some health issues with obesity, but hopefully that's at least a baseline to show that I'm not just making things up.
No_Suggestion_8234 t1_jajzqeu wrote
Interesting, thank you for your response. This is contrary to what I've heard from my PCP so I was curious
deadliftothersup t1_jak27i4 wrote
So my hope and assumption is that they were likely saying "for individual use it's not great" which of course is PCP's bread and butter and on that note I would agree (with some caveats).
Unfortunately I'd like not to doxx myself by showing my own published stuff and having my name out there, but I actually got frustrated at one point in grad school by looking for something novel to say about the predictive value of WHR, circumference, and BMI and after a lot of hours on a really big longitudinal study I came away with "meh, use whichever".
Of course, if I wanna be super accurate, I'm doing a dexa scan or something, but geez human research is already expensive and I could rent this multi thousand dollar machine or just have a cheapo scale and wall height measurement and have it be good enough for research purposes.
Lastly, I think it absolutely must be said that regardless of size, moving more can counteract a ton of this stuff to the point where the negative cardiometabolic effects are hugely diminished. A lower bmi person is absolutely not 1:1 healthier.
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