What physicians get wrong about the risks of being overweight
What physicians get wrong about the risks of being overweight
Stanford medicine statistician Maya Mathur found that doctors have misconceptions about being overweight shortening lifespans.
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When talking in a clinical sense, I think we need to standardize on a numerical standard, like body fat percentage or BMI. It's my understanding that people want to get away from BMI because it's crude, and I agree, but communicating in numbers will make things less confusing. Healthy body fat ranges depend on race, gender, and age, but it would still be better than using words the public has coopted to become unclear.
BMI does use numbers, but is complete pseudoscience, and should absolutely be moved away from.
https://www.npr.org/templates/story/story.php?storyId=106268439
Kinda like the Myers’s Briggs is pseudoscience, and lie detectors, and a lot of other shit we use frequently in society.
I think what we need is just something scientifically based, like at all. Numbers or no numbers.
Calling all of these "pseudo science", shows a gross misunderstanding of either the term, or the subjects mentioned.
If you can show me that any of those things are actually supported by scientific study, I’m happy to learn, but yes, based on everything I’ve learned about them, they are pseudoscience. None of them are supported by any sort of research findings.
It's rather trivial to find a study talking about BMI, but talking about it in extremes like this does no one any good. I would highly suggest you go educate yourself on public health or at least read something in the literature before making such extreme claims. To help you get started, here's a fairly comprehensive review on BMI in the clinical context.
You do bring up a good point in that it's important how we use BMI and just what it represents. Major institutions such as the AMA have started to reassess exactly how BMI is interpreted (and providing guidelines) in the clinical sense, because there are problematic ways to use BMI. Of note, they do not advocate against using BMI, but rather it should be one of many indicators, as that's the basis of differential diagnosis in the first place.
I’ve already educated myself on this stuff, and continue to do so as more information comes out, but thanks.
The condescending tone is classic considering the thing you linked has right in it:
“However, it is increasingly clear that BMI is a rather poor indicator of percent of body fat. Importantly, the BMI also does not capture information on the mass of fat in different body sites. The latter is related not only to untoward health issues but to social issues as well. Lastly, current evidence indicates there is a wide range of BMIs over which mortality risk is modest, and this is age related. All of these issues are discussed in this brief review.”
It’s a poor indicator because it lacks scientific rigor, aka pseudoscience.
The question was whether it was a clinically relevant metric - it is absolutely a useful one. You are correct that it is not an indicator of percent of body fat, it was not designed to measure this and using it for this purpose is mislead. But there's a world of difference between "it's bad at measuring body fat" and "BMI is pseudoscience". It's unfair to characterize it as lacking scientific rigor because there are plenty of scientifically rigorous studies involving BMI. It is extremely useful as a clinical indicator of one's health, in the same way that body temperature can tell us things in the context of other metrics and can also tell us some high level information about a person's general health.
But perhaps most importantly, it's extremely useful when we come to population health where generalized indicators are often more useful than hyper-specific ones. Indicators which are easy to measure and gather from relevant data sources are also often more useful than ones which may be more accurate on a per-individual basis, but less important when measuring the health of entire populations. I apologize for any condescension in my comment, I was suggesting that you become more educated in matters of public health because indicators like BMI are invaluable in this space.
So it is a gross misunderstanding of the term, sad.
Feel free to explain instead of being condescending for no reason, then.
Like I said I’m willing to learn, but from wiki -
Pseudoscience is often characterized by contradictory, exaggerated or unfalsifiable claims; reliance on confirmation bias rather than rigorous attempts at refutation; lack of openness to evaluation by other experts; absence of systematic practices when developing hypotheses; and continued adherence long after the pseudoscientific hypotheses have been experimentally discredited.
If you can tell me how the things I listed don’t fit into that definition, great. Please do so.
I mean, BMI was openly developed, is systematically calculated and described, has been open to evaluation by experts for decades, and has been part of hypothesis development for similar decades. It is, in fact that systematic study that revealed where its use as an estimator or predictor of health had been overstated.
When science falsifies a model, it does not retroactively make the model pseudoscience.
The ongoing adherence to it after being falsified, repeatedly through different studies, applies to BMI, which qualifies it as pseudoscience.
So you are correct, falsification does not make something pseudoscience, but that’s not relevant in this case.
BMI is useful for historical population comparisons because you can calculate it using just height and weight and it's already been in use for a very long time. It's so crude as to be very misleading when applied to individuals, especially if you decide to turn your brain off when deciding how to evaluate the information.
The origins of the calculation are immaterial. It's value is in comparative studies, not direct judgement. The actual judgement of "good" vs "bad" BMI numbers is dumb(ish) but it is good for comparing populations across both time and space.
It’s my understanding that people want to get away from BMI because it’s crude
Pretty much the only people advocating for this are people who get into weightlifting and I'd say the vast majority of them were already in the overweight category before putting on extra muscle. BMI is by no means perfect, but it's actually extremely good at doing what it was designed to do, which is give a quick and easy metric by which to judge someone's general health. It's meant to be a starting point for a discussion around exercise and other more important factors, when it's clinically relevant to do so.
I would disagree that it’s only weightlifters. I’ve competed at an international level in a completely different sport, and my teammates have the same concerns. And this goes for people who have been selected to represent the national team and those who have not.
I’m in a sport where it’s beneficial to weigh less, and many of us are considered overweight by BMI standards.
My sport is not represented in the Olympics, so we are talking (for the most part) about normal people who like to do sport. My teammates are all teachers, doctors, IT professionals. We aren’t people who are paid to workout all day everyday.
I’d argue that many gym-goers who are dedicated (like HIIT classes, cyclers,etc) would also agree that BMI isn’t great. I don’t have any studies on hand to support my experience/anecdotal evidence. But I’ve been in sport and various gyms for 10+ years and all the trainers, coaches and athletes say the same thing: don’t look at the scale unless you need to weigh in.
Healthy body fat ranges depend on race
This isn't really true. Unless what you're suggesting is that there's a biological component of race, which my understanding no scientist suggests. "Normal" ranges depend on race, but it's not like 1 race is healthier at a different weight than another
While race is mostly a social construct, it's easier to use race as shorthand for "populations with long-term historical ancestry in a loosely defined geographical area, accepting that population mixing has been occurring since the dawn of time and will continue to do so into the future" than it is to say that whole thing every time
BUT, it's my understanding that, for example, Pacific Islanders are generally healthy at a higher body fat percentage than other groups of humans.