Join the discussion
Write your take first — we'll ask for email only when you're ready to publish.
- Hacker News
- The revenge of the six-pack. Now we have them as goal beyond aesthetics or vanity.
- This is known since decades. Male type fat, central obesity or belly fat, is much worse than female type, pear-like. Hormones play a role under the hood. I don't know if liposuction would play any preventive role.by tsoukase
- > 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.
by Supersam654 - Visceral fat really is the devil. It's not some inert glob of tissue padding your organs, it's metabolically active in all the wrong ways - increasing inflammation and insulin resistance.
I've stopped worrying about weight (or BMI) and focus solely on waist circumference as a proxy for visceral fat.
by perrygeo - This is new? I thought they have been saying this for yearsby ajma
- I
- They have. BIM is usually talked about in the same breath as waist circumference which would be a better measure of abdominal fat.by basisword
- 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.
by GuB-42 - 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.
by chr15m - 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.by Noaidi
- > Do not give yourself diabetes by eating vast amounts of sugar.
This can help sustain a high level of exercise (the more the better). Certainly don't if you're sedentary, but the sugar during exercise is really helpful for getting in 10+ hours/week of exercise.
by loeg - > Do not give yourself diabetes by eating vast amounts of sugar. If you are doing this, stop. Not having diabetes decreases CVD risk.
Not eating vast quantities of sugar is good advice, but it's not the direct cause of T2 diabetes. The best evidence suggests that T2 diabetes is caused by the accumulation of fat in the liver and pancreas. See the twin cycle hypothesis. To prevent diabetes, one needs to maintain a weight low enough where the body isn't storing fat in the liver and pancreas (everyone has their own individual threshold for this). If you're pre-diabetic, lose enough weight and most people will regain insulin sensitivity.
by zargon - > 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?
by SoftTalker - 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...
by sn9 - 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.by noemit
- A DXA (DEXA) scan will quantify visceral fat for you. This is a non-invasive scan which uses a low-dose x-ray. Most cities have some sort of sports medicine facility where you can get one. It's typically not covered by health insurance but fairly cheap to pay out of pocket.
https://health.ucdavis.edu/sports-medicine/resources/dxa-inf...
by nradov - There are scans for like $50 that will tell you. Google Dexa scan or something like that.
- So this study basically compares,
BMI
Waist circumference (WC)
Waist to hip ratio (WHR)
Subsequent risk of nine cardiovascular/mortality outcomes in >260,000 people followed for ~20 years
To make it even more useful they should have included DEXA scan bodyfat%.
Also, BMI becomes somewhat biased at height extremes because body mass doesn't scale exactly with height². Humans aren't geometrically scaled copies of one another and empirical scaling exponents are often somewhere between 2 and 3. Conventional BMI tends to read relatively high in very tall people and relatively low in very short people. But changing the exponent would only fix one relatively small limitation of BMI
For better height adjusted replacement for BMI itself, one option is Trefethen’s BMI
WHR and WC is positively correlated to bodyfat% but this may get distorted for strongmen or sumo wrestler who tend to have much higher than average lean mass, may also have higher WC and WHR but difference maybe waist to shoulder ratio, they tend to have much bigger and powerful shoulders.
what's interesting is, for sumo wrestlers specifically, WC still correlates strongly with BF% one study reported r ≈ 0.86
There is a category in fitness called "skinny fat" where you are at low bodyweight (so low BMI) but your fat mass is relatively higher when compared to lean mass, so higher bodyfat%
Many skinny fat people refuse to believe they carry higher bodyfat% because they think they've low bodyweight so they can't possibly carry higher fat, which is wrong.
If you are interested in knowing more about bodyfat, this may help you: https://aretecodex.pages.dev/knowledge/measure/bodyfat
- 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.by jamesgill
- If you have a lot of abdominal fat then you also have visceral fat so it's just a proxy
- 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).by strongpigeon
- 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.
by sn9 - Genuine question: What is the difference between overfat and overweight? Isn’t the extra weight in an overweight person comprised of fat?by kennyadam
- 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.by ColdStream
- 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.
by diydsp - Another common misconception is that one is still healthy with high BMI that comes from having lots of muscle. It's not clear that lots of muscle is healthy.by contubernio
- 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?
by folkrav - 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)
- > 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.
by Aurornis - 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/...
by teleforce