Vast majority of U.S. adults do not meet fitness guidelines

I won’t belabor the point much more but I have to ask. If most of those classified as overweight by BMI are as healthy as those with normal BMI (which is what the obesity paradox shows), on what basis do you claim they suffer from “overfatness”? Are you basing your opinion solely on looks?

Seriously, the obesity paradox occurs because the BMI overweight category includes too many people with high muscularity who are actually fit. That means it can’t be a small number.

Which is why BMI shouldn’t be used on an individual basis to estimate health status. I’m not sure what point you are trying to make here.

Everyone who buys clothes knows their waist size.

But you’re now confusing yourself. When analysed for confounding variables, most of those classified as overweight (excluding, say, those with BMIs of 26) aren’t necessarily healthier than those who’re “normal weight”…at least as far as disease states that bodyweight/body composition has a bearing on. Hence the studies you keep citing that state the Obesity Paradox (note not the Slightly Overweight Paradox) does not exist.

To your next point, “overfatness”…Although it’s something that can usually be determined fairly easily by looks /clothing fit/muffin top/bra creep around etc…it generally refers to the ration of muscle:fat/bodyfat %. Of course, poor body composition isn’t just the province of the overweight but just a bit easier to see.

Given that higher BMIs are surely becoming more predictive of excess bodyfat, since the increase in overweight/obesity manifestly is not due to more and more folk resembling Bev Francis or Dwayne Johnson…at least, not here in Colorado and however much folk might wish their chonk were not a combo of subcutaneous, visceral, and, worse…ectopic deposits…I doubt that treating BMI as a worthwhile tool to start ones own self assessment is a bad thing.

When I look up ‘underweight’ in the bmi charts, I find that I am nowhere near underweight even though I am one of the skinniest seniors I know at 6’2”, 160 pounds. When I looked at the cdc stats I learned that roughly 1.6% of the population meets the definition of underweight and over 70% percent of the population now meets the definition of overweight/obese. That raises more questions than I can type with two fingers about how you can meaningfully have this conversation when comparing the relative health risks of being in the lightest 1.6% of the population vs the heaviest 70%.

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One reason for the “obesity paradox” is that fat located subcutaneously instead of centrally (inside the abdomen) doesn’t not cause disordered metabolism.

You have already pointed out the waist-to-height ratio.

People who have high BMI and not muscular can be safe if their fat is located outside the abdomen such as the lower body. That’s a lot of people…but there are also a lot of people with high BMI which is centrally located.

Wendy

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But the averages in stats do suggest otherwise.

It is a fair point.

I am outrunning 20 year olds. As I should be in my early 60s.

Yes and a much better explanation for the occasional disparity between BMI and health outcomes than a large proportion of folk in the overweight and above category because of their muscularity and fitness.

Apple vs pear shaped distribution of excess bodyfat has long been associated with an increase in metabolic dysfunction and its various sequelae. However, there are other consequences to being overweight that are more related to the Earth’s gravitational pull on the M in BMI…and I suspect that’s the case regardless of body composition.

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Perhaps, but the very reproducible observation in multiple countries that people with overweight BMIs have health outcomes similar to those with normal BMIs indicates that the proportion of folks with centrally located fat is about the same for both groups.

In other words, BMI does not correspond to “bad fat” except (perhaps) at the very extremes.

Working in generalities would be the worst of doctors. It would be bad medicine.

If we stick to working in generalities on these threads, we will not discuss anything at all. Just lumping things together.

If you believe that then you are in opposition to the AMA. Here is part f the AMA recommendation on BMI.

…Under the newly adopted policy, the AMA recognizes issues with using BMI as a measurement due to its historical harm, its use for racist exclusion, and because BMI is based primarily on data collected from previous generations of non-Hispanic white populations. Due to significant limitations associated with the widespread use of BMI in clinical settings, the AMA suggests that it be used in conjunction with other valid measures of risk such as, but not limited to, measurements of visceral fat, body adiposity index, body composition, relative fat mass, waist circumference and genetic/metabolic factors. The policy noted that BMI is significantly correlated with the amount of fat mass in the general population but loses predictability when applied on the individual level. The AMA also recognizes that relative body shape and composition differences across race/ethnic groups, sexes, genders, and age-span is essential to consider when applying BMI as a measure of adiposity and that BMI should not be used as a sole criterion to deny appropriate insurance reimbursement… AMA adopts new policy clarifying role of BMI as a measure in medicine

Given the acknowledgement that BMI has very little predictability at the individual level (at best only useful to assess white folks) and the empirical observation that lots of people seen as overweight by BMI are as healthy as those with normal BMI, why bother using BMI? Measuring your waist and height is simple and far more accurate a barometer of your state of health. BMI adds nothing at the individual level. BMI is a data point that has historically been proven to be more misleading than not.

It is like using skull size to estimate a person’s intelligence.

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I was hoping a thick skull was a sign of superior intelligence.

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Of course, I’m pretty sure that opinions on this topic hinge quite heavily on personal experience. One of the things I’ve observed over the years…decades really…of personal training and group exercise instruction is that the strength of folks’ belief in the idea that BMI is a useless tool tends to be proportional to how far north of that BMI of 25 their own bodyweight is. None of us here, I’m sure…we’re all outliers and Legends in Our Own Minds.

For me BMI (22.2) and weight to height ratio (.44) correspond very well as a measure of approximate body composition per caliper use/body composition scale. Now, in order to qualify as merely overweight, I would need to gain over 20lbs in weight. Given that I already have a fairly muscular physique thanks to insight into the value of strength training some 30 odd years ago and consistency ever since, I think the maximum poundage I could expect to add to what’s there already isn’t likely to be much more than about 5-7lbs. That would take a fair bit more work than I’m willing/able to hack along with some pharmaceutical assistance. This leaves about 15 lbs of fat. I think it’s safe to say, regardless of how this adiposity distributed itself, I would look pretty lardy. I doubt my health related biomarkers would stay the same either.

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You should read the FiveThirtyEight article titled, “bmi is a terrible measure of health”

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The ucla study cited in the article is a good read.

Well, of course it is…as a stand alone measure with no other biomarkers noted and given full consideration. Who here has ever had that happen to them? Most folk on annual physical get some sort of physical…with BP measurement, a cursory listen to the chest, bloodwork to include lipids and metabolic panel, no???

I was told by my Doctor to not worry at all about my BMI.
I have a BMI of 29-30.
I weigh myself regularly with a bathroom scale that measures bioelectrical impedance. I am consistently between 11.5-13% percent body fat. I understand that these scales are not perfect, but using the scale, and the opinion of my Doc, I do not put much stock in BMI.

I have no idea if this link is a valid source, but they say this about it: ( copied text is for Men )

Body fat percentage charts: Women, men, and calculations (medicalnewstoday.com)

Age 60–69 years

Category Percentage
dangerously low under 8%
excellent 8 to 19.7%
good 19.8 to 22.6%
fair 22.7 to 25.2%
poor 25.3 to 28.4%
dangerously high over 28.5%

Yup, I guess all those scientists and MDs who have demonstrated the inadequacies of BMI are really just insecure fatties.

Public service message to anyone out there. Do not bother with BMI. Use waist circumference or waist/height ratio (WHtR). All you need is a tape measure. The most dangerous fat is your belly fat. That’s what you need to control.

WHtR in particular works for everyone, regardless of gender or ethnicity.

The history of the BMI:

When it was developed in the 19th century, the BMI formula was never intended as a measurement of health—especially the health of a diverse population. It wasn’t even created by medical experts. BMI came from the work of a 19th century Belgian astronomer who was designing a population census in the Netherlands. His sample group of high-income, mostly white men aimed to estimate typical sizes of the total population for the purpose of distributing resources.

In the early 1900s, studies were done—primarily based on a white, male population—to try to determine the “ideal body weight.” Mixed results from tests of basic tools to measure body fat—like water displacement and skin calipers—led to the conclusion that the simple math of BMI should set the standard. And it’s been that way ever since. Is BMI Accurate? New Evidence Says No | URMC Newsroom

There you go, another person whose health has not been tied solely to BMI :wink:

I too weigh myself regularly on a bio impedance scale and the only metric I trust is body weight…because I can check frequently with 2×20lb and 2x15lb dumbbells and it always comes out at 70lb. The rest…bodyfat %, subcutaneous fat, muscle and bone mass, visceral fat etc I don’t trust for bang on accuracy but follow for any change. I tend to take the view that, if I add a few points in the direction that’s “bad” and the figure is still favourable, it’s good enough. So, I don’t really think I’m 17% or so bodyfat % but , even if I up it to 20%, that’s still reasonable in a 71 year old woman.

Also, I don’t think these figures necessarily reflect fitness in an objective sense (far more fitness focused tests around that probably aren’t routinely applied or asked about in your average doctor’s office)…but it’s sure taken a commitment to following a long term fitness orientated lifestyle to achieve them and that’s for sure

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Glad to read that, I respect your opinion on medical concerns.

BMI used to bug me before I gained some knowledge of it’s shortcomings. I actually don’t want to lose any weight, I feel ( perceive ) that I’m weaker if I go down 5 pounds from where I’m at. So I don’t care if it’s + or - a few pounds, just want to stay in what feels best to me, for what I like to do.

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The ucla study, ama, Harvard and nih have now convinced me that a ouija board would have better predictive value on heart health than bmi. Roughly 54 million Americans labeled obese/very obese have healthy heart markers, and roughly 20.7 million Americans have a normal weight bmi but unhealthy markers.

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That’s interesting…but kind of irrelevant to the point that I was making that was once folk start to trend a fair bit north of a BMI of 25, the extra “weight” is increasingly likely to be due to extra bodyfat as opposed to muscularity…depending on demographic etc.

That the correlation with cardiovascular health (if that’s what you mean by “healthy heart markers”) isn’t quite as linear as one might expect is due to the influence of both fat distribution (as Wendy explained upstream) and genetics (as I’ve described many times)