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.
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.
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.
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.
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
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.
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.
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.
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.
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).
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).
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:
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.
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'
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.
>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.
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.
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.
Would be interesting to see another study with people who do both breakfast skipping and skipping late-night eating.
When I was in my 30s I was a typical woefully sedentary "IT potato" with more than a few extra kilograms around the waist, but today in my early 40s I manage to stay slim and free from diabetes despite being just as sedentary, and I'm convinced that my intermittent fasting is contributing to it:
These days I wait with breakfast until around lunchtime, and I have my last meal for the day between 6 and 8 o'clock in the evening. That is, instead of the usual pattern of eating during nearly two thirds of the day (16 hours) and fasting (sleeping) during one third (8 hours) I've turned it around so that I fast two thirds of the day, while still consuming the same amount of calories.
I think the connection between intermittent fasting and BMI is already well understood: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6832593/. In addition, I frequently see incredible transformations on the IF subreddit. From an evolutionary perspective, it makes sense that our bodies were not designed to be consuming calories every waking hour.
I eat generally once a day, and it just makes managing food much easier. It took a long time to switch but now it takes much longer to get hungry, which means that if I overeat for any reason (say a party or celebration), I can just delay my next day's meal for few hours after usual date and make it smaller so I'm still not all that hungry (and annoyed) in the evening.
When I get ravenously hungry in the morning (which is around 10-11 AM for me, the blessings of remote flexible work) I just get a coffee or a cocoa and that gets me by to the normal meal time (12-14).
I also tried to cut quickly metabolizing food like bread which just makes me hungry earlier.
Yeah, I think I'm getting good results by having a line of 7 as the latest I'll eat. The after 10 snacks were obviously bad, but it is impressive how invisible they were to my attention.
For me, I was in good shape in my 30s. Then the weight started to creep on.
Now I've been having my first meal after lunch, exercising more by walking and snacking less. Too early to tell how it goes long term.
I'm trying to be a little flexible. So if it's 9am and I'm hungry, or I know I'm heading out the house for a busy morning, I'll eat fruit or vegetables. But no bread.
I was pretty sure this is the normal way of intermittent fasting. Otherwise most people i know would almost be doing intermittent fasting all the time.
Same foods, same amounts, but the time span was more typical and covered about 14 hours starting with breakfast around 9 in the morning and ending with a small snack around 11 in the evening (though never close to bedtime).
What I do now is to simply compress the same consumption (including the small snack after dinner) so that it fits in a span of 7 hours on average. I'm flexible with it since some days and schedules call for other plans. My goal is not complicated: eat nothing for an unbroken stretch of roughly 16 hours per day.
I feel like we're in the dark ages with nutritional testing.
Someday this will be cross referenced with genetics.
E.g. If you read about coffee, most report that it's a net positive. Drink more coffee. But if you're a slow metabolizer like myself, the caffeine stays in your system 4X the normal person and actually significantly increases your chance for a cardiac event.
So if you just read the pop-sci articles, kept drinking coffee, but you're the 1/3 of the population that's a slow metabolizer, you've been doing yourself a disservice your entire life. Worse sleep. More anxiety.
My guess would be that it's people drinking diet soda, salad dressing, sugar+cream in their twenty coffees before lunch, and/or bread. It's entirely based on my experience with folks at the office. I, myself, don't eat breakfast for anxiety / gallbladder removal reasons (I also don't eat lunch when I'm not at/close to home for it), and my fat ass is from a horrid soda addiction as a kid.
Sugar and related carbs really is the worst, eat whole plate of baked potatoes and meat, sated for the rest of the day, eat the carb equivalent in pastries and brain is still in "want more" mode...
Readers and especially reviewers need to looking at effect sizes. Not just "was the p value under 0.05 so there is some effect". What a nothingburger.
Let's break it down.
> Breakfast skipping was correlated with BMI (Wald, 5.481, 95% CI, 0.154-0.847, P-value, 0.019).
What that means is that breakfast skipping was correlated with somewhere between no BMI points and 1. We have no way of knowing which from this study. Basically, maybe your BMI goes up a little, but so little as to be irrelevant.
> A positive direct correlation was evident between late dinner intake, BMI, and HbA1c (Wald, 4.210, 95% CI, 0.743-0.993, P-value, 0.04 for HbA1c, and Wald, 6.777, 95% CI, 1.0221-1.165, P-value, 0.009 for BMI).
Maybe eating dinner late increases your BMI by 1 point or so. This is probably the same point they claim you gain from eating breakfast late. The A1c numbers are so close to being statistically insignificant that we can just ignore them.
And that's before you add all of the other problems with the study.
This study shows nothing. Yet another questionnaire based study about nutrition. I wish we could as a scientific community just ban this garbage.
I knew skipping breakfast (and often dinner too) had little effect on weight, after years of that habit.
What did work? Riding my bike on a week-long river-to-river 500 mile bike ride in Iowa this summer! That was a blast, I got stronger and I also lost a few pounds.
I gained weight every RAGBRAI I did. Pie, beer, pork chops, walking tacos. Seems like I was eating or drinking beer every waking minute I wasn't on the bike. Worth it, though.
People who consciously do IF tend to eat healthier, while people who skip breakfast purely because they're lazy tend to eat less healthy food. I don't believe that eating time affects anything. Our caveman ancestors did not eat muesli immediately after waking up, and yet they did not have diabetes.
This doesn't necessarily sound like intermittent fasting. "normal" eating means breakfast to dinner (let's say 8 PM). This is just shifted to let's say lunch to midnight (late night).
Intermittent fasting is deliberate and actual fasting. Skipping breakfast often (but not consistently) probably lead to a greater feeling of hunger, and when combined with perhaps not being hungry in the morning because of the night eating mentioned it's no fasting either.
Kind of, skipping breakfast definitely prolongs the usual nighttime fast whereas eating late definitely shortens it. So if you're doing both you're kind of not changing anything to first order.
In terms of physical effects, someone who is doing intermittent fasting is attempting to deplete their body’s glycogen stores: your body very carefully regulates blood sugar (glucose) and stores a bunch of extra blood sugar in these hairballs called glycogen, stored mostly in the liver and in the muscle: then when your body needs more blood sugar circulating, it chops sugar bits off of the ends of the hairballs, or if it has too much sugar it grows the ends of the hairballs.
The impact of fasting is a difference then between your activity and your intake, right? So if I want to really deplete my glycogen stores completely, I'll go run a marathon, that'll do it. Thinking really hard, like a game of chess, can too. Key to understanding the difference between fasting and late eating/breakfast skipping, is the fact that at night mostly we sleep or sit lazily in front of a TV or so. So by binging food late at night you are kind of doing the exact opposite of fasting, you are raising your blood sugar at the exact time that your body stops moving and your brain isn't thinking so much, so your body isn't processing that blood sugar. You fill up your glycogen stores this way!
What happens when they get too full? Your body raises its blood concentration of a hormone (signaling molecule) called insulin. Muscle cells can take in blood sugar whenever they want, but fat storage cells have a “lock and key mechanism” where the channel to let in the blood sugar is controlled by this hormone, they cannot take it in without the insulin. So you get this insulin spike while you sleep, body is saying “I have too much glycogen, please store some blood sugar as fat so that I can shrink these glycogens into the bloodstream.” And you put on weight. But, by itself this is healthy weight. This is what's called subcutaneous fat, the fat that's living out by the skin, in adipose tissue. What will kill you is the visceral fat, which is a distortion of this process.
To understand this, understand that a cell might not want to take on more blood sugar either. In programming terms, the bloodstream is a message bus, the insulin is a message on that bus, and the cell might want to NACK the message. A fat cell can only hold so much fat before it bursts, when it gets to bursting it needs to divide into two fat cells that are half full. So it needs to shut down, to say no no I am not taking the sugar in right now.
The difference between programming and biology is that these are analog signals, so rather than a binary on/off, ack/nack, the cell reduces its sensitivity to insulin, “I just won't take on so much blood sugar right now.”
Type 2 diabetes, what this study is talking about, is a disorder where you have a high blood sugar because your body is developing an insulin resistance. So if one cell down-regulates insulin, great, it is protecting itself. But if all your cells do this at the same time then the body can't clear the blood sugar. So what do you do? Analog system. You spike the insulin even higher. “But Mommy I don't want more”—“well TOO BAD finish your plate, we can't have this food going bad in the fridge and we don't want to attract bugs and DO AS I SAY!!”.
As this starts to happen, you start getting fat deposits in places that are not off in secure storage out by the skin, but are sitting close to the organs where they can do real damage to the ongoing function of your cells—visceral fat.
I hope that helps, the idea is that to first order there is no difference in the amount that you fast but only when you are fasting, and the serendipitous overlap of fasting with sleep and low activity is potentially disturbed by late eating and skipping breakfast, and that could be dangerous because if you are already in that hypernourished situation where you are putting on weight, then this puts potentially a larger strain on it during the night time, like it would be worse if you did late night snacking and also had breakfast, but the idea is that maybe even when you try to skip the breakfast to make up for it it isn't all a wash, it really matters when you eat maybe.
I'll wait until they start posting studies about what happens to people a few years after they stop taking this next revolution - do they bounce back more than control or less?
I can see from my Oura ring data that late night eating is hard on the body and the harm is correlated with the how heavy the meal was.
The issue is that it takes work to digest food. Your body does not get to rest as well when you eat late at night. You see it in your heart rate / hrv. Small amounts of carbs don't seem to matter much. A big protein meal is the worst.
yeah but going to sleep hungry, for me at least, is the absolute worst feeling. For me it's not just a matter of heart rate, if i'm hungry there is a good chance I will get no sleep at all. So if i end up for whatever reason not eating ahead of time.... kind of screwed...
All the people in the study already had type 2 diabetes. What would have been useful is to compare their breakfast skipping and late night eating habits (slightly more than half of the people in the study did these activities) against the habits of the general population? As it is, this study tells us nothing.
I will bet on the usual confounding variables when it comes to lifestyle study. Highly likely that eating late at night means coming home late, probably due to working late which probably means a more stressful life. Sadly they are controlling for a chokingly low amount of variables so we will never know.
I question the population focus and it's applicability to Western, specifically American, diets. The study focused on 310 diabetic patients in Saudi Arabia. I don't think it is going out on a limb to say that there are dietary differences between the typical Saudi Arabian diet and the typical American diet, especially in the overwhelming reliance on ultra-processed, pre-packaged foods in the U.S.
Perhaps this might have more applicability to diabetic patients in Europe, specifically those who follow the Mediterranean diet due to socio-geographic reasons.
Besides the mention of BMI by other users, I'd also ponder the study's applicability because of its focus on men and women in a city in Saudi Arabia, where cultural norms are likely at odds with more western sensibilities (e.g. access to sport amenities for women patients, etc.).
> Breakfast skipping and late dinner intake were associated with obesity, while only late dinner consumption was associated with poor glycemic control.
So they measured that if one doesn't eat breakfast they were more likely to be obese than people that did eat breakfast?
Imagine if the study said the opposite. HN would praise it and the thread would be filled with positive anecdotes. No questions asked. But now when it goes against the popular narrative everyone does everything to discredit it. Classic HN behavior.
Damn. I thought skipping breakfast is good for adults (I'm 40).
Anyway, let's say late night eating is bad. But many programmers I know (including myself) are more productive at night. But working = hungry. How do you handle this contradiction?
As usual, it's from people pushing their beliefs and/or their products on the public to serve their own purposes; further, as with so many modern ills, we can put some of the blame on Edward Bernays.
I would love to see a study where they compare the skip-breakfast/eat-late behavior to circadian rhythm and then normalize for that to see if people who work to their actual circadian rhythm are less likely to be diabetic than the 8-5 crowd. Because I know that left to my own devices, I wake at 10am, eat at noon, and go to sleep at 1am, but "real life" means I wake up 4 hours "off schedule" so my diet clock doesn't match my sleep schedule.
lol when I was at my heaviest, I often skipped breakfast. I must have been an IF champ...people online would have been envious of my routine. i could have sold a diet book about it. as it turned out, this could be explained simply by the fact i had eaten so much for dinner and before bed that i was full in the morning from still digesting the food. meh.
BMI is often inadequate to evaluate an individual, but it has proven effective for measuring across larger sample size, since its coarseness will swing both ways and more or less cancel out.
Spot on. And let's be honest even at the individual level - you know whether your BMI is "high" because you are a muscular jock or just an average joe that (over)eats the wrong things and is a couch potato (same probably applies to the ultra-lean runner types on the low side).
How do you measure effectiveness ? I am under the impression we have very few (any?) large scale intervention that have an objective positive effect, I'd be glad to know more.
Clarification unrelated to the BMI comment, but the writeup isn't from nih.gov. The article is found through PubMed, a search engine and data repository. Your article was published in the 'British Journal of General Practice'. OP's article is from 'Cureus'. PubMed just has copies of the articles.
Saying its ironic that nih.gov has both articles is somewhat like saying its ironic that Google has any two articles.
Disclaimer directly from the linked webpages: "As a library, NLM provides access to scientific literature. Inclusion in an NLM database does not imply endorsement of, or agreement with, the contents by NLM or the National Institutes of Health. Learn more about our disclaimer."
While for individual cases clinicians shouldn't rely on BMI much, and only use it for screening, in studies it makes sense to use it because it's a useful tool. A person with a BMI of 30 is almost always fatter than a person with a BMI of 20. The outliers (like athletes with big bones) wouldn't change the statistical analysis.
It's in the same boat with IQ, it's a useful tool if you accept it has limited uses.
For one thing, it does a terrible job for tall people.
https://www.fatcalc.com/bf lists several alternatives, along with their estimated accuracies. BMI is the least accurate method short of taking a wild guess.
No discussion of what they eat.
What a waste of time for everyone involved.