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by howeyc 1039 days ago
They interviewed 310 ppl, calculated their BMI, then found out around half skip breakfast. That half had BMI a little higher than the rest.

No discussion of what they eat.

What a waste of time for everyone involved.

3 comments

On one hand, I like the publishing policy of NIH, because more dissemination of information is a good thing.

But on the other, so many people gloss over or are just blatantly unaware that NIH specifically doesn't endorse anything about anything published there, that they're just a clearing house. And then people either infer authority from the domain, or they use that to consciously or subconsciously push their belief.

It is the National Library of Medicine, which is a database maintained by NIH.

The journal this article is from is from is Cureus: https://www.cureus.com/

Their tagline seems to be "publishing beyond open access" and to my eye at least looks like a 3rd tier journal.

But NIH really has nothing to do with it, they're just a catalog. Libraries have tons of bullshit in them. You are supposed to be the filter.

The authors correlated late night eating and HbA1c. That's more relevant to people with Type 2 diabetes than the general population.

The authors found no correlation between skipping breakfast and HbA1c. That's also more relevant to people with Type 2 diabetes than the general population.

Managing type 2 diabetes can occupy a non-trivial amount of mental space. Though probably not as much as managing type one diabetes.

Not everyone is in everyone intended audience.

And BMI says nothing of body fat percentage

Can have higher BMI and lower bodyfat

I'm not convinced BMI is a useful metric

Why do people keep making this argument? It's a terrible argument.

BMI and body fat are extremely strongly correlated. People with a very high BMI are all obese or morbidly obese. And people with a very low BMI are almost all underweight. BMI is a very simple, easy to calculate and useful metric. It works across countries and across time.

BMI is just one metric. It doesn't tell you everything and knowing only the BMI of an individual isn't proof of anything. But average BMI is higher in Texas than Vietnam despite Texas having way more more bodybuilders. People in Texas have higher BMI because people in Texas are fatter. That's the truth. BMI denialism confounds me.

> People with a very high BMI are all obese or morbidly obese.

That is tautological - obesity is defined in terms of BMI. BMI over 30 is obese.

Arnold Schwarzenegger is 6'2" and weighed 235lbs at contest (30.2 BMI) and 260lbs in the off season (33.4 BMI). So much for your "all" claim.

> Arnold Schwarzenegger is 6'2" and weighed 235lbs at contest (30.2 BMI) and 260lbs in the off season (33.4 BMI). So much for your "all" claim.

Most people aren't Arnold. Outliers don't count in studies, for very good reasons.

It is understood that when we say "all" we mean "close to 99%", and for 99% of the population with a BMI over 30, they are overweight.

I wouldn't make the all claim, but you must admit that a world renowned body builder is an extreme outlier. Obviously a DEXA scan would be far more accurate, but it seems clear from the literature I've read that BMI is a pretty good guide for most people.
Arnie is also called an outlier. You don’t dismiss BMI just because. A doctor will factor that in before declaring a patient unhealthy. Otherwise, it works for most people and might be appropriate in large studies.
> Arnold Schwarzenegger is 6'2" and weighed 235lbs at contest (30.2 BMI) and 260lbs in the off season (33.4 BMI). So much for your "all" claim.

Congratulations on discovering that tail ends of distributions exist.

It doesn't invalidate anything in the comment you are responding to.

Well, thankfully people in real life have eyes and brain and can seee that someone is just a heavy pile of muscle vs donut cosplayer, i.e can spot the 0.1% of muscle mass builders from the 99.9% of fatsos.

"A metric have 0.1% outliers so it is bad metric" is a horrible take

The model disregards ridiculous outliers like world class bodybuilders in order to be simple and useful for the other 99.999% of society.
According to BMI I spent years "obese" and am now "overweight" bordering on obese.

I'm about 16-18% body fat. I'm definitely muscular, but hardly in the .0001%. If I'm wearing a shirt, you can't really tell that I lift.

Hardly world class.

Is your sense that having excessive muscle weight is somehow healthy in a way that isn’t reflected in the BMI classification?
A lot of people are pointing out Arnold as your example, but fail to mention he first won the Mr Olympia more than 50 years ago! Our understanding of exercise and nutrition has improved since those times. You no longer have to be an outlier in genetics or dedication to achieve good results.

I'm far from a genetic outlier, but I go to the gym for 3-4 60-90 minute sessions a week. My program is efficient, I don't take steroids, and my nutrition is decent (but not great). I'm 5'10" and 202 pounds (29 BMI).

I find it disingenuous that people use the top performers as an excuse. There is a middle ground where a modest investment will reap significant returns.

If maintaining the healthy function of my body is skewing my BMI as to be useless, then perhaps BMI is a poor metric.

> Arnold Schwarzenegger is 6'2" and weighed 235lbs at contest (30.2 BMI) and 260lbs in the off season (33.4 BMI).

I understand what you're saying, but I think a person that wins Mr. Olympia seven times is clearly a severe, severe, severe outlier. For a decade he was THE most well-built body on the planet. Literally ONE in 5 billion.

Obviously no measurement is "perfect" for "everyone", but BMI is a very good indicator for an extremely high percentage of the population.

For the average person that isn't doing something radical with their body for a specific goal (powerlifer, bodybuilder, olympian, etc.) BMI is a fantastic first pass indicator of how things are going general health/weight wise.

Most people are fat. BMI is accurate for 99+% of people.
Severe obesity is 40+ BMI. About 1 in 16 children and adolescents ages 2 to 19 (6.1%) have severe obesity, according to niddk.nih.gov. It's a staggeringly high percentage of the population.

Even when you take a 1 in 5 billion outlier like Arnold he still doesn't come close to crossing this threshold, despite his high calorie body-builder diet.

Oh yeah that probably explains the US’ obesity epidemic. It’s in fact a body builder epidemic. Problem solved!
I thought this was well known. I’ve not known a gym that takes BMI seriously. People like Messi who are relatively lean and fit are overweight per the BMI scale.

There exist better metrics as well

It’s because people take their BMI and become shocked about where they land. It takes like a small beer gut to land in to obese.

BMI isn’t generally used as a picture of overall health anyway. More often, it’s used as a measure for health issue probability. As Texas BMI raises, it can be used to calculate the increasing chances of a huge variety of health problems.

Well, not so small unless you also exercise reasonable amount and have some muscles.
> BMI denialism

You've already pointed out that it depends on what you're using it for, and that's it's not especially useful on an individual basis. Why the weird Holocaust association?

BMI isn't a great measure for a lot of reasons.

There's way too much variation in height and muscle mass. There's variation based on race as well, for example CMS has different standards for DPP eligibility if you're asian [1].

BMI was created in 1830, and has always been of limited usefulness. There are much better methods for measuring health in relation to total body fat.

It is completely reasonable to be critical of it [2] when it's used improperly (which is very common).

[1] https://www.medicare.gov/coverage/medicare-diabetes-preventi...

[2] https://www.medicalnewstoday.com/articles/255712

yeah... but the likelihood that you have a high BMI because you're just so jacked is low.

It's not perfect, but it's a good metric.

I'm firmly in the 'overweight' category based on BMI, at 15% bodyfat, and I wouldn't classify myself as jacked. I have a bit more lean muscle than most from cycling but definitely not a 'gym body'.
Yeah, I'm 'overweight'. I run a lot and generally in pretty good shape. But I could absolutely lose 10-20 lbs of fat. Just because you're a little overweight doesn't mean you're unhealthy.
If you could lose 10-20 lbs of fat (and don't just mean, you have 10-20 lbs of fat left), then tautologically it would be healthier if you did lose the weight. The degree to which it makes you healthier is debatable, but that extra weight isn't making you more healthy (outside of people that are very underweight).
Sure, it's not an emergency but I try to eat better.
yeah pretty much. a lot of guys who do even a little physical labor for a living or hobby are easily in the overweight category despite being strong and not that fat at least going by visual appearance . such as guys in construction, landscaping, or moving. a lot of people who are borderline obese do not even look that fat especially clothed. the stereotypical 'fat guy' with the overhanging or balloon stomach is more like a BMI of 40.
Although this has little bearing on the study, BMI works best for people of average height. Tall thin people have a high BMI, and unthin short people have a low BMI.

Math reason: the square term for height is incorrect, people are three dimensional and a cube would be more appropriate (the formula is (lbweight/(inchheight^2 * 703))).

Check the BMI of tall and short people that you know in this chart:

https://www.cancer.org/cancer/risk-prevention/diet-physical-...

It’s really not a good metric. It’s incredibly noisy. “Are you fat” isn’t something that needs a noisy metric. And it makes analyses messy when bmi is used as a measure of fatness.
Are you maybe hoping for a metric of general healthiness? Measuring body fat accurately on your own is tough. Most people know their height and can find a scale to use so you can get a rough idea of what bucket you're in. It's good for most people. If you're working out and pretty athletic idk why you'd stress about your bmi being a little high.
> If you're working out and pretty athletic idk why you'd stress about your bmi being a little high.

If you’re not working out and fat, BMI is still not a good descriptor of “how fat” or “how consequentially fat”.

And yet you’ll still get scientists mapping out correlations and then it’s a shitty analysis because it does not show what the study assumes.

sadly it's often misused. When there are things like BMI qualifications on medical interventions or where jobs have physical requirements.

I knew a guy who really wanted to join the fire service but couldn't meet the BMI requirements as he was in the 'obese' BMI bucket, In this case he was just very broad and very muscular (built like the colloquial brick shithouse). By their requirements jonah lomu would not have been able to join because he was 'obese'

That's crazy. A lot of the firefighters I see are uh, fairly big people. The test should be the physical exam.
please delete your comment for going against bmi = health/fitness orthodoxy
Most people you see at a gym will probably be classified as 'overweight'. The fact of the matter is muscle is counted against you in BMI, and it takes very little to cross into the 'overweight' threshold. I would have to cut down to around 12% or lower body fat to be considered 'healthy', and I'm far from jacked.

1. Being sub 12% body fat (the highest BMI that would be considered healthy) is arguably unhealthy in and of it's own

2. Being on the low end of healthy would be, if my math serves me, -2.5% body fat

3. BMI does not distinguish between unhealthy / overweight, and fit / healthy (which should be the primary goal of such a metric?)

4. BMI aligns the best outcomes with those that will minimize muscle mass

It's not that BMI does not have it's place, but let's call a spade a spade.

99.99% of people BMI works just fine. As it turns out, most people in the western world are fat.

The musclebound people literally do not care about BMI because its irrelevant to them. Almost everyone else, should probably start eating less.

>Being sub 12% body fat (the highest BMI that would be considered healthy) is arguably unhealthy in and of it's own

12% body fat isn't a BMI, what are you trying to say?

BMI is not supposed to bucket you into healthy or unhealthy. It is a ratio of your weight to height. You're right that there are a lot of people who are overweight but are perfectly healthy. I think your problem is that you're viewing BMI as some kind of blanket good or bad health number. It is what it is, and it's just one aspect of your physical health, which you probably shouldn't be trying to capture in a single number anyway.

Go get a physical exam from a doctor if you want something comprehensive. If you just want a general height/weight ratio, BMI is pretty good for most people.

>12% body fat isn't a BMI, what are you trying to say?

it seems likely parent is talking about his* required body fat to be considered in the "healthy" BMI range (under 25 for males).

Most people don’t go to a gym.
I think you have a misguided idea that most people at the gym are buff, muscular, etc...

This couldn't be further from the truth.

> Being sub 12% body fat (…) is arguably unhealthy in and of its own

How so? A couple years ago I was at 10% and running a ½ marathon three times a week. I felt pretty healthy.

Pretty much only true if you are a body builder or someone else with an unusual amount of muscle mass relative to your height. For the vast majority of people though BMI is fine.
Very tall and very short people can also have BMI's that don't make sense.
There is little point of doing a study based on BMI when what you want is body fat. BMI is imperfect. It’s fine when you want to give people a quick metric for them to assess their fitness by themselves. People who are extremely fit with a high BMI already know they are extremely fit after all. It’s not fine when you want to analyse the effect of different life styles.
It’s easier to gather hundreds of people’s BMI for a study than it is to measure fat, which can also be misleading depending on the method used.
It's even easier to not do the study if you are going to use bogus data anyway.
It is for studies because, the average person with a high BMI has higher body fat on average.

That might not be the case individually but with multiple people the few outliers don't matter.