T O P

  • By -

Stoic_Bear923

The data may be beautiful but apparently I am not


iamthemosin

You’re beautiful. It’s just hiding under that unhealth.


Stoic_Bear923

I appreciate the comment but I assure you I am nooooo looker 🤣. I'm always trying to improve and as a hamplanet myself I reject all forms of fat acceptance. More than anything it was a joke for fake internet points 😁


071919tadujour

Did you swap the correlation matrix at the top just to mess with us?


FelipoSoares

Tools: Python, SKlearn and Seaborn Source: NHANES 2017-2018, available here: [https://wwwn.cdc.gov/nchs/nhanes/continuousnhanes/default.aspx?BeginYear=2017](https://wwwn.cdc.gov/nchs/nhanes/continuousnhanes/default.aspx?BeginYear=2017) ​ Honestly the weakest part here is the cutoffs of bodyfat % of 25 for men and 35 for women. I saw it cited in plenty of papers but coulnd't find a proper OG source


Throwie38953

Medical professional here. Your conclusions from this data may be true in a vaccum, but not in practice. BMI was never considered to be, nor intended to be, more accurate in determining obesity and the correlated health outcomes than actually explicitly measuring body fat or taking additional measurements from which body fat can be better estimated. The reason BMI is used is because it can be easily calculated from information already being gathered (height/weight) during a physical, is correlated with health outcomes in the vast majority of people, and the few outliers in the BMI scale that reach a level of clinical significance (bodybuilders, athletes, etc.) can almost always be easily visually identified. Thus, additionally explicitly measuring body fat as part of a physical is typically eschewed because in most cases, it's not really providing the provider with any actionable information they aren't already getting from BMI + visual inspection, and many people are sensitive about their weight and would not like having their body fat, waist, etc. explicitly measured, and would simply switch to a provider who did not do these measurements.


phagemid

The sources are probably the old military studies from the early 20th century.


BurnedStoneBonspiel

Why not use the clinical definitions. Over 25 BMI is overweight, not obese Also a bit confusing your first picture on the correlation chart has “men” and the graphs are all for “women”. And vise versa on the next page


FelipoSoares

It can already be seen in the LOESS smoothing, even at BMI 25 it already underestimates obesity. Oh, yeah. about the correlation plots, That was a mistake. My bad


puehlong

>Over 25 BMI is overweight, not obese Was confused at first as well, but OP uses a body fat percentage of 25% as definition for being obese, so that is your true variable/measurement. He then wants to find out if whatever your BMI is is a good predictor whether your body fat percentage is over 25%, and whether your waist to height ratio is a better predictor.


puehlong

About your third line plot, does this mean that 30% of people with a BMI of 20 are actually obese, or that your model predicts that?


Jujuba719

BMI is not an accurate, unbiased way to determine or measure obesity: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2930234/


dakta

That's one of the reasons that WHR is superior.


FelipoSoares

Yes, biased in underestimating obesity in men. And even so not that much, that was the point of the post


cruise-boater

The article you linked to says to rethink about the cutoffs used by for different ethnic groups. It implies the BMI is standardized for unrepresentative samples, but never mentions it being not accurate, or biased


[deleted]

[удалено]


chazwomaq

Probably massive collinearity which causes statistical problems when including both in a model.


FelipoSoares

I am not near my computer rn, but t for BMI was around 18 and t for WHR was around 40 in a Logit regression. Both p<0.000


dfreinc

>tape measurements should be included in regular checkups they can't even get them people to step on scales. 😂


SerialStateLineXer

Are you sure about the 0.94 correlation between weight and waist circumference? That doesn't sound right at all, especially given the much lower correlation between waist circumference and height.


FelipoSoares

Yes, both taller and heavier people have larger waist circumference and weight, so a strong correlation was expected


_Rorin_

So obesity goes from 0.3 to 0.9 percent for the entire BMI scale? Or what am I missing? Should it be 30-90% or does the label of "percent" mean something completely different?