Relatedly, there is evidence that certain types of "resistant starch" can help reduce visceral fat. This starch comes from green bananas, potatoes, legumes, etc. It has to be either raw (there are supplements for this) or cooked and cooled.
"Resistant starch intake facilitates weight loss in humans by reshaping the gut microbiota"
For non-invasive heart disease risk prediction nothing beat ECG, period.
Somehow American Heart Association and its European counterpart are in denial, and still pushing dinasour screening mechanism with very low accuracy for heart disease risk prediction.
The standard risk model for CVD based on PREVENT (US) and SCORE-2 (Europe) like parameters are very poor as reported in the recently published paper on the their accuracy performance by the Swedish team [1]. As all CVD risk stratification with cardiologist review (expert-in-the-loop), the most important accuracy metric is sensivity/recall (avoiding false negative that will escape review) of PREVENT and SCORE-2, 26% and 48%, respectively.
The paper alternative proposal increased the sensitivity to 58% by performing clustering instead of conventional regression models as practiced in the PREVENT and SCORE-2.
These type of models including the latest proposal performed very poorly as indicated by their otherwise excellent and intuitive display of graphical abstract results [1].
[1] Risk stratification for cardiovascular disease: a comparative analysis of cluster analysis and traditional prediction models:
Get as many scans you can under insurance. Data is king and Claude happens to chew it all pretty well. Apple Health data by itself and family history is enough to make a starter PDF for your cardiologist.
Getting an ECG, EKG, TTE, CAC, carotid duplex US, lipid panel, CMP, TSH, 25-OH Vit D, B12 + folate were what my cardio recommended before appointment #2 on hypertension. Both of us are data guys.
Huh? I get a blood panel every year and 90% of the things it looks for are normal year after year. But there is always 1 or 2 things flagged that I need to pay attention to.
An ECG if it was just part of the normal yearly panel of things that get looked at I don't think ppl will stop doing it just because it doesn't find something right away
I thought this was pretty well known already. Being “overfat” is the problem, not being overweight (though they’re often correlated). BMI is really easy to measure, and is mostly accurate, that’s why it’s so pervasive. However it remains a pretty rudimentary metric (and really should use the third power or your height instead of the second).
> BMI is really easy to measure, and is mostly accurate, that’s why it’s so pervasive.
BMI is easily misunderstood by people who know just enough to see that it’s imperfect, but not enough to understand why it’s still a valuable screening tool.
I’ve been in the “overweight” BMI range with low body fat before. It’s not too hard to get there if you’re lifting weights and paying attention to your diet consistently for years, but it takes a lot of work to get there. It doesn’t happen accidentally except for people who win some genetic lottery to build a lot of muscle and keep body fat low without trying.
Getting all the way to the obese BMI range while having healthy body fat is only happening for people with an extreme dedication to body building and diet (and let’s be honest, a lot of the people in this category are manipulating hormones too).
Yet whenever BMI comes up some people try to dismiss it as too flawed based on these possible edge cases. The edge cases for BMI exist, but that doesn’t mean it’s not useful. It’s a good general purpose screening tool with numbers that are available. If someone has more precise measurements available, those should be used instead. BMI is a really good first pass screener to determine if a closer look should happen.
Yeah, people don't want to understand that your body structure messing with BMI is quite real but only a few points. It's unquestionably "wrong" in scoring me higher than my wife despite the fact that she's the one with a few extra pounds. But it scores us both as normal, the difference doesn't matter.
>Getting all the way to the obese BMI range while having healthy body fat is only happening for people with an extreme dedication to body building and diet
And sumo wrestlers.
The line seems to be drawn at (effortful) activity level more than anything else. And BMI doesn't say anything about that.
I think the vexation comes from the focus on an attribute that is not directly mutable, per one's agency, because that's easier to sell things related to. Versus action that you have a lot more direct control over (social or physical circumstances notwithstanding).
The farther from average height you are the worse it is. If you are from some part of the world where the average height distribution is near the point BMI based itself you will perceive it to be so much better.
I am only 6' and only an intermediate lifter. I'm overweight, but BMI makes me look obese. It really only takes a normal person a year or so to get to three plates on squat with no supplements other than chicken broccoli and rice if they don't skip workouts. Assuming no injuries. That level of strength easily distorts bmi wildly if you are even a little taller than average.
BMI is at best 66% accurate, so "mostly" is correct, but what is mostly good enough for?
BMI has known biases in gender, age, and race. It misclassified Asians, women, elderly w sarcopenia, and people with high body fat to lean tissue ratio.
Yes, it is a pretty high level metric with good correlation a bunch of diseases, but really many of these is because it is ALSO correlated to percent of fat, which is often the more relevant metric. But as you said BMI is so much simpler to measure.
Many active gym people have pretty high BMIs but fairly low fat (because muscle is dense), and unsurprisingly have better outcomes than the average person (if you ignore the share that uses/overuses anabolic steroids and co)
> Many active gym people have pretty high BMIs but fairly low fat (because muscle is dense),
I’ve been in the overweight BMI category with low body fat by being active at the gym and focusing on diet. It takes some work to get there.
If I check the calculators for the obese BMI range, there was no way I could get there without either gaining a lot of fat on top of the muscle. The amount of muscle required to have an obese BMI with healthy amount of fat is absurd.
> Many active gym people have pretty high BMIs but fairly low fat
I think this is greatly exhaggerated.
Yeah you can put on as much muscle as Arnold and have a FFMI of about 27 then maybe have a BMI of 34 if you have 20% body fat.
But a very gifted natty might cap out at maybe 24 with a BMI of 30 at 20% bodyfat. But let's be realistic. This is not "many active gym people". This is the guy winning the local strongman meet.
Yes a couple of years training for most people can add a couple of points to BMI but I think people exaggerate how much this is. Go look at a 20lb brisket at costco - you don't see people with that much extra muscle all that often.
I do agree to some extent, but really the overweight threshold for BMI is 25. And 30 for obese.
At 6 feet / 183 cm that it takes 184 lbs / 83 kg to be overweight. From what I could find, for regular gymgoers the typical weight for people around 6feet is 180-190lbs, which put many people around the overweight threshold. I am myself at 24.9, and while not skinny I am definitely in the skinnier half of the people at my local gym.
Do you have a citation for that? I've had thoughts in a similar direction (specifically around the upper/lower intervention points) but have had no luck finding data.
Not sure I follow the logic here, but happy to be proven wrong if I'm misunderstanding. It's not intuitive to me that a 300 lb. person at 20% body fat is generally at the same risk as a 200 lb. person at 30% body fat.
Fat is inherently unhealthy for you beyond some low baseline level.
Additional muscle is positive for health, but only up to some reasonable threshold. There is no health benefit to having very high levels of muscle, and in fact it may be negative for your health at extreme levels. E.g. many bodybuilders have trouble breathing, sleep apnea etc.
Both people in the example have 60lbs of fat. 1lb of muscle doesn't cancel out the negative health effect of 1lb of fat
Looking for some references on these claims, thanks! What you're saying registers as "makes some sense, but where's the evidence?" to me. I'm not seeing the connection where total lbs of fat is inherently worse than higher percentage.
Some are more common in short people and some are more common in tall people. Hypertension is one of the ones more common in short people and is significantly more common than the rest combined, so your overall chance of having some form of heart disease goes down as you get taller. However, the forms of cardiovascular disease more common in tall people (e.g. atrial fibrillation) are more likely to actually kill you.
How accurate is it, in practice, for a given individual? I'm not that out of the ordinary proportion wise. I have a slightly longer torso and arms versus my legs, a somewhat muscular-ish baseline and broad shoulders, but I accumulate fat almost exclusively abdominally. My teenage self, lifetime peak of my fitness, no visible body fat, hyperactive football player, qualified as solidly overweight. If I was to listen to it, I'd be called obese before I noticeably start to show body fat.
I often wonder far from the median I am in this regard. I was under the impression that it was pretty accurate for assessing populations, but fell apart very quickly at the individual level. How many "normal"/otherwise healthy people do fall outside BMI's numbers?
It's not really intended to be applied to individuals at all, but if you're in the "healthy" BMI range then you are probably fine just not thinking any further about your weight and doing something like measuring your body fat percentage would just be a waste of time and a source of stress for some people. If you're outside that range, then it is worth doing some of the more involved things to judge if your weight is healthy.
It’s a tool not the tool. If you have obese BMI you can… look in the mirror and see how accurate it is. If you aren’t sure take one of the dozens of other tests. People focus too much on it being a one stop shop - it’s not. It’s the start of a dialogue with your pcp and self on assessing your health that’s highly correlated with poor health outcomes.
That was my impression as well. I'm just wondering if there are actual numbers to gauge by how much. I'd find it almost concerning anyone would draw any conclusions from it if it's not significantly any better at predicting health outcomes than a coin toss.
Yeah BMI is sort of a 'good enough' technique but also has some very obvious areas that it can miss. If you fall outside the typical fat to muscle ratio is a good example.
A muscular person can be "overweight" by BMI standards but not overfat at all. This is the case for many types of athletes, specially in strength disciplines but not only. It is the case in the fitness world that people ignore BMI and are intesterested in body-fat-percentage instead. This is hard to measure accurately so not so useful metric for the general population.
It's also possible to be overfat without being overweight! These "skinny fat" people often look normal enough but they carry very little muscle. It is a concerning condition because a doctor might not recommend a normal-weight person to hit the weights.
I like to think of this as four quadrants around two axes. Low fat/low muscle is simply skinny. High fat/high muscle is the "big guy/gal" look that I associate with laborers. Low fat/high muscle is an athletic look; unhealthy in extremes (bodybuilding) but generally desirable. High fat/low muscle is skinny fat, which I associate with sedentary knowledge workers.
I've been considered borderline or obese by the standard BMI index for 20 years at least, but for a lot of that had very little to no visible extra weight. A lot of that was just plain having more muscle than the average the standards are built around, but I also suspect BMI gets to be really inaccurate for tall people. I would look anorexic if I had to drop enough weight to be considered not overweight.
"Overweight" can mean the same thing for weight, but it also refers to those with a BMI specifically between 25 and 30, and those with BMIs greater than 30 are classified as "obese".
The dominant discrepancies are "expected" fat (boobs, etc), and "unexpected" muscle (cyclists, body builders, hard labour careers, etc). I'm currently around 10-15lb overfat and 40-50lb overweight [0]. Only the former statistic matters.
[0] And that, at least somewhat, tracks visual perceptions. Nobody looks at me with a shirt on and believes I need to lose weight, because 10-15lb isn't _that_ much extra on a tall frame. If I were 40-50lb overfat then that would be painfully obvious regardless.
It's specifically a high level of visceral body fat.
Genetics determines which parts of the body gain fat first as you gain fat overall, and some people have the unfortunate genetics to gain it first viscerally and some people have the fortune to gain it there last (and everything in between).
This means that you can have different people with the same body fat percentage but drastically different disease risks.
But yes this was also known already.
That's why it's been recommended to take a waist measurement alongside BMI to get a much more informative screening tool. Waist-to-height ratios are another alternative.
A nitpick about the title: Not strictly abdominal fat, but visceral abdominal fat, which surrounds the organs. Not all abdominal fat is visceral; in fact, in many people the majority is not.
The article mentions visceral early on, which is the subject.
> Those with obesity and low WC [waist circumference] were not found to be associated with a significantly different risk of outcomes compared with those who had normal weight and low WC, except for all-cause mortality, for which risk was significantly lower.
If I'm reading that right, it sounds like obesity (and therefore BMI) is still a better predictor for all-cause mortality. Perhaps waist circumference is better at predicting cardiovascular risk but BMI is still useful.
Same for me, no one considers BMI to be a good indicator of anything, but it is better than nothing, and more importantly, it is super simple.
Any idiot with a bathroom scale and a measuring tape can do it. And by adulthood, height doesn't change significantly and you probably know it, so you may not even need that measuring tape. Other metrics need specialized equipment, error prone or complex procedures, etc... I don't even know how to make a waist measurement. Where exactly? How relaxed should the subject be? How long after eating?...
That's the value of BMI: simple repeatable. Not the best but enough to get and idea and make statistics.
> And by adulthood, height doesn't change significantly and you probably know it ...
But height does change in adulthood [0]. On average people living past 40 gradually lose height. At age 80, it's likely height loss will be >=2 inches. This loss is reflected in higher BMI even when body fat content hasn't changed. Average BMI increase isn't large, but think about a person losing 4 or 5 inches of height while maintaining body fat unchanged.
Self-reported height is generally greater than measured height. Adding 1/2 to 1 inch is common (per experience measuring height). "Height inflation" has modest effect on BMI but problematic in research and workup for medical procedures. In the latter cases, measuring height is necessary.
Cutting saturated fat to under 15g per day and increasing intake of viscose fibre (e.g. beans) will reduce your LDL particle count in a few weeks, which reduces your CVD hazard ratio. You can measure your LDL and look up the papers yourself. Statins will reduce it a lot too (potentially with side effects). Replace solid fats like butter with liquid fats like olive oil.
Literally any amount of regular exercise, including walking, will decrease CVD HR. The more the better (up until quite a large amount e.g. professional athlete). The more your heart is steadily pumping during exercise the better. Every bit helps reduce CVD risk. Movement is medicine.
For the love of God do not smoke. Literally one of the surest ways to die a horrible death. Stopping smoking reduces CVD risk by a large amount.
Do not give yourself diabetes by eating vast amounts of sugar. If you are doing this, stop. Not having diabetes decreases CVD risk.
Other factors you probably can't change so focus on these.
Doctors, if I got anything wrong please correct me.
You said all this like you know something, but you didn’t bring up oxidative stress once. I mean, smoking is the leading cause for increasing oxygen stress in the body so you kind of mentioned it there but oxidative stress can be controlled with nutrients like zinc, copper, and manganese.
> Studies have shown that visceral fat, which is fat that surrounds the internal organs in the abdominal area, is associated with chronic diseases like heart disease and diabetes, while subcutaneous fat, which is located directly under the skin, is not as strongly associated.
How does one determine if one has an excess of visceral fat?
whats wild is there are people who look very fat - who have lots of subcutaneous fat, who don't have visceral fat. The excessive subcutaneous fat can be hard on your joints but doesn't seem to correlate to other health issues.
The irony of BMI is that people with plenty of muscle mass are more likely to have a high BMI as well as lowered risk for heart disease.
BMI was never meant to be used as a diagnostic measure. BMI is just a rough filter for large data sets, and entirely dependent on the average height and habits of that population.
Anyone taller than about 6'3" could tell you the recommended weight according to their BMI has always been absurdly low. If it's a printed chart on the wall, they might not even be on it.
BMI is not a good metric for really short and really tall people.
The "ideal weight" of a person is proportional to height to an exponent somewhere between 2 and 3. Simple physics would say 3 but because tall people are not just scaled up copies of small people, it is closer to 2 in practice, maybe around 2.3, but we say 2 because it is easier to calculate.
The downside is that BMI overestimates the "ideal weight" for short people and underestimate it for tall people. But BMI is not great at capturing exceptions anyways, so there is little interest in "fixing" this.
This is a common misconception. BMI while an ok population metric, for individual's the biggest problem with is its poor sensitivity - it fails to classify people as obese who are obese.
Using your 6 3" male as an example, they are significantly more likely to be clinically obese (using waist circumference, body fat % etc) at a weight lower than BMI cut-off of 240 lbs.
For two people that are the same height, one could have X lbs of pure muscle, and one could have X lbs of pure fat, and they would have the same BMI. Color me shocked that it is not always a good predictor of disease.
Maybe the olympic athletes that are pushing their bodies to achieve the limits of human capability, yes. I think it's obvious why some (not "ALL") of them die young.
You're not going to die of a heart condition if you hit the gym 3 times a week.
Also nobody says "don't eat food" other than thinspo instagram pages. You should eat food, if you don't eat food you die.
Relatedly, there is evidence that certain types of "resistant starch" can help reduce visceral fat. This starch comes from green bananas, potatoes, legumes, etc. It has to be either raw (there are supplements for this) or cooked and cooled.
"Resistant starch intake facilitates weight loss in humans by reshaping the gut microbiota"
https://pmc.ncbi.nlm.nih.gov/articles/PMC10963277/
Edit: Ah, HN submission 2 years ago: https://news.ycombinator.com/item?id=39592367
I feel like I've heard this story 1 million times before.
For non-invasive heart disease risk prediction nothing beat ECG, period.
Somehow American Heart Association and its European counterpart are in denial, and still pushing dinasour screening mechanism with very low accuracy for heart disease risk prediction.
The standard risk model for CVD based on PREVENT (US) and SCORE-2 (Europe) like parameters are very poor as reported in the recently published paper on the their accuracy performance by the Swedish team [1]. As all CVD risk stratification with cardiologist review (expert-in-the-loop), the most important accuracy metric is sensivity/recall (avoiding false negative that will escape review) of PREVENT and SCORE-2, 26% and 48%, respectively.
The paper alternative proposal increased the sensitivity to 58% by performing clustering instead of conventional regression models as practiced in the PREVENT and SCORE-2.
These type of models including the latest proposal performed very poorly as indicated by their otherwise excellent and intuitive display of graphical abstract results [1].
[1] Risk stratification for cardiovascular disease: a comparative analysis of cluster analysis and traditional prediction models:
https://academic.oup.com/eurjpc/advance-article/doi/10.1093/...
Get as many scans you can under insurance. Data is king and Claude happens to chew it all pretty well. Apple Health data by itself and family history is enough to make a starter PDF for your cardiologist.
Getting an ECG, EKG, TTE, CAC, carotid duplex US, lipid panel, CMP, TSH, 25-OH Vit D, B12 + folate were what my cardio recommended before appointment #2 on hypertension. Both of us are data guys.
How many ECGs can you sell vs how many other snake-oil products? :)
(Edit: This is intended to be sarcastic. I agree 100% with the comment)
(Edit 2: Added the smiley face)
>How many ECGs can you sell vs how many other snake-oil products?
A lot, probably. You could sell people on the idea that it should be a part of your yearly health screening.
"And if you really care about your health you should do them every 3 months to catch problems early!"
or some such.
This will work short-term sure, but after about lets say, 3 years of no adverse findings, the average person will not take it seriously anymore.
Huh? I get a blood panel every year and 90% of the things it looks for are normal year after year. But there is always 1 or 2 things flagged that I need to pay attention to.
An ECG if it was just part of the normal yearly panel of things that get looked at I don't think ppl will stop doing it just because it doesn't find something right away
> the average person
I do not consider the average HN commenter to be average.
“You’re waiting 3 months between ECGs?”
Whistle: Hope you didn't burn those arteries there mate :)
You can still sell snake oil that's purported to improve ECGs.
We should talk, if you can't beat 'em, join 'em :)
Poe's law in a full swing.
I didn't know... Thank you
I thought this was pretty well known already. Being “overfat” is the problem, not being overweight (though they’re often correlated). BMI is really easy to measure, and is mostly accurate, that’s why it’s so pervasive. However it remains a pretty rudimentary metric (and really should use the third power or your height instead of the second).
> BMI is really easy to measure, and is mostly accurate, that’s why it’s so pervasive.
BMI is easily misunderstood by people who know just enough to see that it’s imperfect, but not enough to understand why it’s still a valuable screening tool.
I’ve been in the “overweight” BMI range with low body fat before. It’s not too hard to get there if you’re lifting weights and paying attention to your diet consistently for years, but it takes a lot of work to get there. It doesn’t happen accidentally except for people who win some genetic lottery to build a lot of muscle and keep body fat low without trying.
Getting all the way to the obese BMI range while having healthy body fat is only happening for people with an extreme dedication to body building and diet (and let’s be honest, a lot of the people in this category are manipulating hormones too).
Yet whenever BMI comes up some people try to dismiss it as too flawed based on these possible edge cases. The edge cases for BMI exist, but that doesn’t mean it’s not useful. It’s a good general purpose screening tool with numbers that are available. If someone has more precise measurements available, those should be used instead. BMI is a really good first pass screener to determine if a closer look should happen.
> screening tool
People tend to think in absolutes. Even perfectly rational people fall logically foul to not considering outliers.
Yeah, people don't want to understand that your body structure messing with BMI is quite real but only a few points. It's unquestionably "wrong" in scoring me higher than my wife despite the fact that she's the one with a few extra pounds. But it scores us both as normal, the difference doesn't matter.
Anything to pretend they aren't too heavy.
>Getting all the way to the obese BMI range while having healthy body fat is only happening for people with an extreme dedication to body building and diet
And sumo wrestlers.
The line seems to be drawn at (effortful) activity level more than anything else. And BMI doesn't say anything about that.
I think the vexation comes from the focus on an attribute that is not directly mutable, per one's agency, because that's easier to sell things related to. Versus action that you have a lot more direct control over (social or physical circumstances notwithstanding).
> The lifestyle has a negative effect on their health, with sumo wrestlers having a much lower life expectancy than the average Japanese man.
(from https://en.wikipedia.org/w/index.php?title=Sumo&oldid=136533...), so I'm not sure this is a counterexample.
The farther from average height you are the worse it is. If you are from some part of the world where the average height distribution is near the point BMI based itself you will perceive it to be so much better.
I am only 6' and only an intermediate lifter. I'm overweight, but BMI makes me look obese. It really only takes a normal person a year or so to get to three plates on squat with no supplements other than chicken broccoli and rice if they don't skip workouts. Assuming no injuries. That level of strength easily distorts bmi wildly if you are even a little taller than average.
IIRC, the farther you are from an "ideal" 19th century Frenchman, the less BMI says about you.
BMI is at best 66% accurate, so "mostly" is correct, but what is mostly good enough for?
BMI has known biases in gender, age, and race. It misclassified Asians, women, elderly w sarcopenia, and people with high body fat to lean tissue ratio.
Yes, it is a pretty high level metric with good correlation a bunch of diseases, but really many of these is because it is ALSO correlated to percent of fat, which is often the more relevant metric. But as you said BMI is so much simpler to measure.
Many active gym people have pretty high BMIs but fairly low fat (because muscle is dense), and unsurprisingly have better outcomes than the average person (if you ignore the share that uses/overuses anabolic steroids and co)
> Many active gym people have pretty high BMIs but fairly low fat (because muscle is dense),
I’ve been in the overweight BMI category with low body fat by being active at the gym and focusing on diet. It takes some work to get there.
If I check the calculators for the obese BMI range, there was no way I could get there without either gaining a lot of fat on top of the muscle. The amount of muscle required to have an obese BMI with healthy amount of fat is absurd.
> Many active gym people have pretty high BMIs but fairly low fat
I think this is greatly exhaggerated.
Yeah you can put on as much muscle as Arnold and have a FFMI of about 27 then maybe have a BMI of 34 if you have 20% body fat.
But a very gifted natty might cap out at maybe 24 with a BMI of 30 at 20% bodyfat. But let's be realistic. This is not "many active gym people". This is the guy winning the local strongman meet.
Yes a couple of years training for most people can add a couple of points to BMI but I think people exaggerate how much this is. Go look at a 20lb brisket at costco - you don't see people with that much extra muscle all that often.
I do agree to some extent, but really the overweight threshold for BMI is 25. And 30 for obese.
At 6 feet / 183 cm that it takes 184 lbs / 83 kg to be overweight. From what I could find, for regular gymgoers the typical weight for people around 6feet is 180-190lbs, which put many people around the overweight threshold. I am myself at 24.9, and while not skinny I am definitely in the skinnier half of the people at my local gym.
I believe evidence points towards absolute level of fat being more important than % for overall health.
E.g. 20% bodyfat at 250lbs is still a lot of fat.
Of course it's difficult to ever get very high on absolute fat if at 15% or below.
Do you have a citation for that? I've had thoughts in a similar direction (specifically around the upper/lower intervention points) but have had no luck finding data.
Not sure I follow the logic here, but happy to be proven wrong if I'm misunderstanding. It's not intuitive to me that a 300 lb. person at 20% body fat is generally at the same risk as a 200 lb. person at 30% body fat.
Fat is inherently unhealthy for you beyond some low baseline level.
Additional muscle is positive for health, but only up to some reasonable threshold. There is no health benefit to having very high levels of muscle, and in fact it may be negative for your health at extreme levels. E.g. many bodybuilders have trouble breathing, sleep apnea etc.
Both people in the example have 60lbs of fat. 1lb of muscle doesn't cancel out the negative health effect of 1lb of fat
Looking for some references on these claims, thanks! What you're saying registers as "makes some sense, but where's the evidence?" to me. I'm not seeing the connection where total lbs of fat is inherently worse than higher percentage.
You won’t find any reference for those claims. Did you know that the majority of people who have heart attacks have normal lipid levels?
It’s not the fat that kills. It’s oxidated lipids that kill.
Do short people have much lower risk of heart disease?
Some are more common in short people and some are more common in tall people. Hypertension is one of the ones more common in short people and is significantly more common than the rest combined, so your overall chance of having some form of heart disease goes down as you get taller. However, the forms of cardiovascular disease more common in tall people (e.g. atrial fibrillation) are more likely to actually kill you.
Does that have to do with sizes of the heart and few other organs apparently being largely constant regardless of height?
How accurate is it, in practice, for a given individual? I'm not that out of the ordinary proportion wise. I have a slightly longer torso and arms versus my legs, a somewhat muscular-ish baseline and broad shoulders, but I accumulate fat almost exclusively abdominally. My teenage self, lifetime peak of my fitness, no visible body fat, hyperactive football player, qualified as solidly overweight. If I was to listen to it, I'd be called obese before I noticeably start to show body fat.
I often wonder far from the median I am in this regard. I was under the impression that it was pretty accurate for assessing populations, but fell apart very quickly at the individual level. How many "normal"/otherwise healthy people do fall outside BMI's numbers?
It's not really intended to be applied to individuals at all, but if you're in the "healthy" BMI range then you are probably fine just not thinking any further about your weight and doing something like measuring your body fat percentage would just be a waste of time and a source of stress for some people. If you're outside that range, then it is worth doing some of the more involved things to judge if your weight is healthy.
If bmi says you're obese, you very likely (~95%) are. The problem is that bmi only catches about half of people who are obese.
https://www.nature.com/articles/s41598-020-69498-7
It’s a tool not the tool. If you have obese BMI you can… look in the mirror and see how accurate it is. If you aren’t sure take one of the dozens of other tests. People focus too much on it being a one stop shop - it’s not. It’s the start of a dialogue with your pcp and self on assessing your health that’s highly correlated with poor health outcomes.
It isn't accurate. It is a statistical tool meant for easily measuring populations of people. It does not apply in any meaningful way to individuals.
That was my impression as well. I'm just wondering if there are actual numbers to gauge by how much. I'd find it almost concerning anyone would draw any conclusions from it if it's not significantly any better at predicting health outcomes than a coin toss.
Yeah BMI is sort of a 'good enough' technique but also has some very obvious areas that it can miss. If you fall outside the typical fat to muscle ratio is a good example.
Which for the majority of the population isn't relevant.
The people most obsessed with "BMI isn't accurate" are overweight people making excuses for themselves.
Genuine question: What is the difference between overfat and overweight? Isn’t the extra weight in an overweight person comprised of fat?
A muscular person can be "overweight" by BMI standards but not overfat at all. This is the case for many types of athletes, specially in strength disciplines but not only. It is the case in the fitness world that people ignore BMI and are intesterested in body-fat-percentage instead. This is hard to measure accurately so not so useful metric for the general population.
It's also possible to be overfat without being overweight! These "skinny fat" people often look normal enough but they carry very little muscle. It is a concerning condition because a doctor might not recommend a normal-weight person to hit the weights.
I like to think of this as four quadrants around two axes. Low fat/low muscle is simply skinny. High fat/high muscle is the "big guy/gal" look that I associate with laborers. Low fat/high muscle is an athletic look; unhealthy in extremes (bodybuilding) but generally desirable. High fat/low muscle is skinny fat, which I associate with sedentary knowledge workers.
Different athletes look different. A runner vs a Olympic powerlifter vs a quarterback.
I've been considered borderline or obese by the standard BMI index for 20 years at least, but for a lot of that had very little to no visible extra weight. A lot of that was just plain having more muscle than the average the standards are built around, but I also suspect BMI gets to be really inaccurate for tall people. I would look anorexic if I had to drop enough weight to be considered not overweight.
Not necessarily, a bodybuilder or very athletic person might be overweight in the sense of above average for their height but not overfat.
"Overfat" just refers to having too much fat.
"Overweight" can mean the same thing for weight, but it also refers to those with a BMI specifically between 25 and 30, and those with BMIs greater than 30 are classified as "obese".
The dominant discrepancies are "expected" fat (boobs, etc), and "unexpected" muscle (cyclists, body builders, hard labour careers, etc). I'm currently around 10-15lb overfat and 40-50lb overweight [0]. Only the former statistic matters.
[0] And that, at least somewhat, tracks visual perceptions. Nobody looks at me with a shirt on and believes I need to lose weight, because 10-15lb isn't _that_ much extra on a tall frame. If I were 40-50lb overfat then that would be painfully obvious regardless.
What is the line for "overfat" in this framework?
But it's actually not just being "overfat".
It's specifically a high level of visceral body fat.
Genetics determines which parts of the body gain fat first as you gain fat overall, and some people have the unfortunate genetics to gain it first viscerally and some people have the fortune to gain it there last (and everything in between).
This means that you can have different people with the same body fat percentage but drastically different disease risks.
But yes this was also known already.
That's why it's been recommended to take a waist measurement alongside BMI to get a much more informative screening tool. Waist-to-height ratios are another alternative.
A nitpick about the title: Not strictly abdominal fat, but visceral abdominal fat, which surrounds the organs. Not all abdominal fat is visceral; in fact, in many people the majority is not. The article mentions visceral early on, which is the subject.
If you have a lot of abdominal fat then you also have visceral fat so it's just a proxy
This is not true.
It is what is called “skinny fat“.
> Those with obesity and low WC [waist circumference] were not found to be associated with a significantly different risk of outcomes compared with those who had normal weight and low WC, except for all-cause mortality, for which risk was significantly lower.
If I'm reading that right, it sounds like obesity (and therefore BMI) is still a better predictor for all-cause mortality. Perhaps waist circumference is better at predicting cardiovascular risk but BMI is still useful.
This is new? I thought they have been saying this for years
I
and because it is comparative ratio (cm / cm), it works in any length metric. CMIIW
They have. BIM is usually talked about in the same breath as waist circumference which would be a better measure of abdominal fat.
Same for me, no one considers BMI to be a good indicator of anything, but it is better than nothing, and more importantly, it is super simple.
Any idiot with a bathroom scale and a measuring tape can do it. And by adulthood, height doesn't change significantly and you probably know it, so you may not even need that measuring tape. Other metrics need specialized equipment, error prone or complex procedures, etc... I don't even know how to make a waist measurement. Where exactly? How relaxed should the subject be? How long after eating?...
That's the value of BMI: simple repeatable. Not the best but enough to get and idea and make statistics.
> And by adulthood, height doesn't change significantly and you probably know it ...
But height does change in adulthood [0]. On average people living past 40 gradually lose height. At age 80, it's likely height loss will be >=2 inches. This loss is reflected in higher BMI even when body fat content hasn't changed. Average BMI increase isn't large, but think about a person losing 4 or 5 inches of height while maintaining body fat unchanged.
Self-reported height is generally greater than measured height. Adding 1/2 to 1 inch is common (per experience measuring height). "Height inflation" has modest effect on BMI but problematic in research and workup for medical procedures. In the latter cases, measuring height is necessary.
[0] https://www.uhhospitals.org/blog/articles/2024/10/why-do-peo...
You can control your CVD risk.
Cutting saturated fat to under 15g per day and increasing intake of viscose fibre (e.g. beans) will reduce your LDL particle count in a few weeks, which reduces your CVD hazard ratio. You can measure your LDL and look up the papers yourself. Statins will reduce it a lot too (potentially with side effects). Replace solid fats like butter with liquid fats like olive oil.
Literally any amount of regular exercise, including walking, will decrease CVD HR. The more the better (up until quite a large amount e.g. professional athlete). The more your heart is steadily pumping during exercise the better. Every bit helps reduce CVD risk. Movement is medicine.
For the love of God do not smoke. Literally one of the surest ways to die a horrible death. Stopping smoking reduces CVD risk by a large amount.
Do not give yourself diabetes by eating vast amounts of sugar. If you are doing this, stop. Not having diabetes decreases CVD risk.
Other factors you probably can't change so focus on these.
Doctors, if I got anything wrong please correct me.
You said all this like you know something, but you didn’t bring up oxidative stress once. I mean, smoking is the leading cause for increasing oxygen stress in the body so you kind of mentioned it there but oxidative stress can be controlled with nutrients like zinc, copper, and manganese.
> Studies have shown that visceral fat, which is fat that surrounds the internal organs in the abdominal area, is associated with chronic diseases like heart disease and diabetes, while subcutaneous fat, which is located directly under the skin, is not as strongly associated.
How does one determine if one has an excess of visceral fat?
A waist measurement is the cheapest and simplest way other than just looking.
You want to make sure you measure under similar conditions, like in the morning after relieving yourself (for example).
If it's too high, losing a ~0.5-1 lbs per week while strength and endurance training with progressive overload will get it down sustainably.
https://www.barbellmedicine.com/blog/visceral-fat-waist-vs-w...
whats wild is there are people who look very fat - who have lots of subcutaneous fat, who don't have visceral fat. The excessive subcutaneous fat can be hard on your joints but doesn't seem to correlate to other health issues.
There are scans for like $50 that will tell you. Google Dexa scan or something like that.
take a look at myticker.com
(previously at https://news.ycombinator.com/item?id=45857053)
It doesn’t matter how fat you are or how much cholesterol you have in your blood. What matters is the oxidative stress that oxidizes the lipids.
They need to figure out a way to reliably Measure OXLDL.
The irony of BMI is that people with plenty of muscle mass are more likely to have a high BMI as well as lowered risk for heart disease.
BMI was never meant to be used as a diagnostic measure. BMI is just a rough filter for large data sets, and entirely dependent on the average height and habits of that population.
Anyone taller than about 6'3" could tell you the recommended weight according to their BMI has always been absurdly low. If it's a printed chart on the wall, they might not even be on it.
BMI is not a good metric for really short and really tall people.
The "ideal weight" of a person is proportional to height to an exponent somewhere between 2 and 3. Simple physics would say 3 but because tall people are not just scaled up copies of small people, it is closer to 2 in practice, maybe around 2.3, but we say 2 because it is easier to calculate.
The downside is that BMI overestimates the "ideal weight" for short people and underestimate it for tall people. But BMI is not great at capturing exceptions anyways, so there is little interest in "fixing" this.
This is a common misconception. BMI while an ok population metric, for individual's the biggest problem with is its poor sensitivity - it fails to classify people as obese who are obese.
Using your 6 3" male as an example, they are significantly more likely to be clinically obese (using waist circumference, body fat % etc) at a weight lower than BMI cut-off of 240 lbs.
It only fails to classify people with excess body fat who are in the healthy weight range.
It's really good at catching people who are obese who are overweight.
Americans that are 6'3" (190.5cm) are about 1.5% of the population. It is a tiny fraction of the population.
The 2000's called. We've known this for decades because we did a LOT of studies back in the day when you could still get government funding.
For two people that are the same height, one could have X lbs of pure muscle, and one could have X lbs of pure fat, and they would have the same BMI. Color me shocked that it is not always a good predictor of disease.
My problem is it’s usually the second guy advancing this argument.
“Be athletic don’t eat food” they said
Then basically ALL the athletes die young lol. Particularly of heart conditions
Idk guys
Maybe the olympic athletes that are pushing their bodies to achieve the limits of human capability, yes. I think it's obvious why some (not "ALL") of them die young.
You're not going to die of a heart condition if you hit the gym 3 times a week.
Also nobody says "don't eat food" other than thinspo instagram pages. You should eat food, if you don't eat food you die.