15 ms·

People with low BMI aren't more active, they are just less hungry, 'run hotter'

_aavaa_ 4y ago
"The investigators acknowledge some limitations on this research, including the fact that although they measured food intake, *they didn't measure what the participants were actually eating or their feelings of satiation or satiety*." This seems to directly contradict the title. EDIT: What food they are eating and how satiating that food may be is irrelevant. They did not measure the participants feelings of satiation or satiety. The title can't claim that the lower BMI people feel less hungry if you don't measure how hungry they feel.
- burlesona 4y ago
  I think they are saying the caloric intake was measured, but they didn’t distinguish between what kind of food the calories were coming from: > The participants were monitored for two weeks. Their food intake was measured with an isotope-based technique called the doubly-labeled water method, which assesses energy expenditure based on the difference between the turnover rates of hydrogen and oxygen in body water as a function of carbon dioxide production. Their physical activity was measured using an accelerometry-based motion detector. Also regarding the specific food choices: > The team is now expanding its research, including studies that include these measures. They also plan to look at genetic differences between normal weight and healthy underweight individuals. Preliminary analysis suggests single nucleotide polymorphisms in certain genes that might play a role.
  - deleted 4y ago
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  - _aavaa_ 4y ago
    I don't see how that has any impact on my point. title: "People with low BMI aren't more active, *they are just less hungry*, 'run hotter'" quotation: "they didn't measure what the participants were actually eating or *their feelings of satiation or satiety*" The title is factually untrue. You can't claim that people with lower BMI "are just less hungry" if you don't measure how hungry they feel.
    - phkahler 4y ago
      Depending what you eat, it's possible to basically eat all you want and still lose weight. One example is learning to love non-carb foods - eat all the antipasto salad and steak you like (expensive AF yes).
      - lazide 4y ago
        Which doesn’t refute the point the post you are replying to made at all.
      - FollowingTheDao 4y ago
        > One example is learning to love non-carb foods This could be true for some people, but not for everyone, which is where this research will lead. With all the love of science here why does no one think genetics matters when it comes to diet and health?
    - burlesona 4y ago
      OK, I see what you mean. However I would interpret the fact that people consistently ate less as strongly implying that they were less hungry in the first place. While one individual might go around hungry, in general people don’t experience hunger if they don’t have to. I think if they had substituted “eat less” for “are less hungry” the title would be fair.
  - jstanley 4y ago
    Title says they are less hungry, researchers say they didn't measure feelings of satisfaction or satiety. I think that contradcits the title.
- beanjuice 4y ago
  Caloric intake is a measure of the energy we receive from food accurately, i believe they are referring more-so to an idea in a recent popular HN post, potatoes,[1] and which foods are more filling. It could be that there is error in what the less-eating participants happen to eat more-filling food, but not that the entire hypothesis would be incorrect. [1] https://dynomight.net/potato-diet/ https://dynomight.net/potato-diet/
- deleted 4y ago
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- dontlistentome 4y ago
  Totally agree with your point and find it really annoying. The original journal entry is titled: 'Higher than predicted resting energy expenditure and lower physical activity in healthy underweight Chinese adults.' and makes no such 'less hungry' claim. That appears to have been introduced from the 'cell press' journal/article promoting organization.
  - FollowingTheDao 4y ago
    Did you read the full study?
arcanus 4y ago
"We expected to find that these people are really active and to have high activity metabolic rates matched by high food intakes," says corresponding author John Speakman, a professor at the Shenzhen Institutes of Advanced Technology in China and the University of Aberdeen in the UK. "It turns out that something rather different is going on. They had lower food intakes and lower activity, as well as surprisingly higher-than-expected resting metabolic rates linked to elevated levels of their thyroid hormones."
- causi 4y ago
  Makes me wonder, if thyroid disorders can cause obesity, can thyroid-modifying therapy or exogenous thyroid hormones treat obesity?
  - tapland 4y ago
    I've been on and off thyroid medication since my early teens and bounced about 40 lbs up and down during it. My hormone issues were first found because I gained weight while being a competitive young athlete. I think the same range is pretty common for people with certain other medications. The whole dieting discussion, all nutrition advice, kcal in/out goes out the window when your metabolism is a black box. Afaik there still isn't any study showing that any dieting works long term? So if we want to fight an obesity epidemic more needs to be done than to shift blame to affected individuals.
  - lazide 4y ago
    Common symptoms of thyroid disorders include obesity and/or excessive thinness (not anorexia per-se, but it can look like it), along with a cornocopia of other issues. Certain mental disorders (depression and anxiety) also highly correlate with obesity and/or underweight. A common treatment for ADHD (stimulants) often gets folks to a healthy weight that previously struggled on one side or the other. It’s a complex problem, with a lot of ever changing variables we have little insight into. Anecdotally, I know of several boomers that had serious thyroid issues likely tied to exposure to the Santa Susana Field Lab and Nevada nuclear testing. They were consuming milk and other products from areas contaminated by them at the right times. All the various plastics we’ve all been exposed to and other various chemicals are also likely doing something too. But also, the whole country has gotten dramatically more sedentary and media consumption focused, and the media keeps getting more and more anxiety inducing and alienating. As a country, we all need to ‘get out and touch some grass’ more too.
shay_ker 4y ago
Is this paper peer-reviewed?
- gjsman-1000 4y ago
  Does it matter? Many scientists in the know say that peer review is as good as a trashy spam filter these days. This isn't to say that it is absolutely useless, more that it is very overrated.
  - BitwiseFool 4y ago
    I like to think of "peer review" in the same way as "peer code review". Just because someone looked at it and approved it doesn't mean that it is free of shortcomings and defects.
    - gjsman-1000 4y ago
      Not just "peer code review" from a good friend or someone working on the same project as you - a review from somebody who has a ton of stuff to review at once, in many different areas, and very limited time to do it.
      - lazide 4y ago
        Still better than something someone didn’t even bother trying to peer review, usually.
        lvass 4y ago
        Not always. As academia becomes increasingly autocratic and contaminated by power, peer reviews become a marker for group-think, and placing relevance into peer review is a mechanism to empower the oligarchy and suppress technical dissidence, therefore anti-scientific.
      - HelloMcFly 4y ago
        I do peer review, and know colleagues that do as well. I'd say the median number of articles reviewed per person in a given year is 10. I don't claim to represent most reviewers, but I also don't think a presumption that reviewers primarily only have time to half-ass it is fair either.
gjsman-1000 4y ago
To be fully honest - I can relate to this. During my college years, I ate a full-size burger, potato fries, and soda every day for lunch for ~2 years. I never got fat and retained a healthy BMI, never crossing 200lbs despite being a 6'2" male - even though I almost never exercised and spent almost all day sitting working in the Math Lab. I did skip breakfast regularly so maybe that had something to do with it. My family on seeing the portion size (particularly the potato fries - think 3x a McDonalds large fries) thought it must be my brain consuming those calories or something.
- sdfhdhjdw3 4y ago
  > all day sitting working in the Math Lab What I tell people is that my powerful brain needs a lot of calories.
  - deleted 4y ago
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- mason55 4y ago
  What did you eat for the rest of the day? Even if that meal was 2k calories, if you walked around campus a bit and ate moderate breakfasts and dinners then it’s not that crazy. It’s hard to get fat from one bad meal a day. What typically gets people is eating their daily needs via meals and then having high calorie snacks on top of that.
  - the_only_law 4y ago
    Yeah it took me a while to realize why I could eat huge servings of the worst fatty, carb filled, sugary, etc. foods available and not gain weight. Then I noticed, that despite looking like a large meal, the calories weren't that high.
- corrral 4y ago
  4k+ per day of junk food from ages ~15-20. Then I had to knock it off because I stopped being able to do that while staying trim (got fat fast, and I really was trim before). Which is probably just as well because that wasn't healthy anyway. Dunno where it was all going. I wasn't really getting much bigger or taller for most of that span.
FollowingTheDao 4y ago
My family has Sami heritage, we run cold. My average body temp is 96.8 degrees. We also have trouble with hyperlipidemia, obesity, and early heart disease. So the genetics of all of this will be interesting. I have managed to avoid my family curse by eating pretty much only fish and game meat, like a Sami. And I do not eat much. It was the only diet that would raise my HDL.
- deleted 4y ago
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- sgt 4y ago
  Samis are also pretty small people. Almost like elves. That can actually be an advantage for longevity in some ways.
  - FollowingTheDao 4y ago
    Yeah, we are all short stature as well. If fact, my older brother was given growth hormones as a young child because he was not "growing as expected". Idiots. All Inuit populations are shorter on average.
    - sgt 4y ago
      That's terrible! Hope they put an end to that.
- giantg2 4y ago
  I'm surprised how little is said about traditional diets. It's like everyone has to have the same numbers, diet, etc. If they don't, then it's automatically statins or bust.
  - FollowingTheDao 4y ago
    Yes, but "traditional diets" for who? An Inuit? A Mediterranean farmer? A Sri Lankin Indian? Our traditional diets changes our genetics, so who you are will determine what is healthy for you. I agree with the statin. They tried to force them on me. I took a look at my genetics, changes my diet accordingly, and LDL and HDL reversed in three weeks and I have the blood work to prove it.
2OEH8eoCRo0 4y ago
I've always been told that I'm a "furnace" but I don't think that I'm less hungry. BMI of 19.5
- toomuchtodo 4y ago
  What's really needed is a statistical analysis such that 23andme would do, where you can take a matrix of people and their SNPs via genotyping, and then compare that to measured BMRs (basal metabolic rates). The switch that controls this is either genetic, gut flora, or a combination of the two. This leads me to believe the treatment will be either CRISPR or gut flora protocols (similar to how fecal transplants have altered the BMI state of the recipient [1]). [1] https://www.google.com/search?q=fecal+transplant+bmi https://www.google.com/search?q=fecal+transplant+bmi
  - FollowingTheDao 4y ago
    ...with a focus on Mitochondrial Genetics. Regarding the gut, should probably take a peek at FUT2 genetics: https://www.sciencedirect.com/science/article/pii/S2352345X21000424 https://www.sciencedirect.com/science/article/pii/S2352345X2...
the_only_law 4y ago
Seems to line up with my experience, am always burning up (until I turn on the AC and freeze) Especially at night though I have to to jack the temperature down or I won't sleep. Also less hungry aligns pretty well. Unfortunately when I get hungry, it's normally "a little hungry) at akward spread out intervals. I probably feel most hungry after midnight but never eat then because well, I have to sleep soon. I've tried to put on weight before, but I could never stomach massive calories dense meals, without horrific nausea and discomfort.
- sleepydog 4y ago
  If you run hotter, wouldn't you feel less hot? Since your normal temperature would be that much higher than the ambient temperature. At least, when I have a fever I feel cold, even though I'm hot.
  - JumpCrisscross 4y ago
    Speaking anecdotally, my body temperature tends to run above average and I have a body that is shit at throwing off heat. I have dark skin yet still managed to get sun stroke earlier this week in the Mediterranean because my biology prefers me lightheaded than sweating. Morning run in the snow and t-shirt, on the other hand? Easy peasy.
  - JacobThreeThree 4y ago
    It seems like the study used metabolic rate (energy/time unit) and thyroid activity, not body temperature. That being said, metabolic rate probably correlates with body temperature, but that's not clear. What's interesting is that these people kept a high metabolic rate while doing less activity. It's almost like, if you rest more, your body will have the energy to increase its metabolic rate, or it could be totally physiological and it depends on the person.
  - derefr 4y ago
    Feeling cold in a fever is a specific lie your brain tells your body, to trigger shivering, so that your skeletal muscle will help to heat you up even faster. Usually, when you're hot, you feel hot.
mrhands556 4y ago
I have a really low BMI but also I definitely run cold. My wife and I regularly fight over the thermostat.
- carbadtraingood 4y ago
  Do you run cold or feel cold? Because those are opposite. If you run hot, temperatures should feel relatively chilly. Like when you run a fever you feel cold.
  - m0llusk 4y ago
    Fever is the immune system fighting infection. The better comparison is to light exercise which increases temperature and perceived temperature. Perceived internal temperature is in general most closely related to movement.
- FollowingTheDao 4y ago
  Feeling cold and having a low body temperature are not equivalent. Take your temperature as soon as you wake up for a week to know your normal resting temperature.
sudden_dystopia 4y ago
The study was underweight bmi vs healthy bmi. Nothing about overweight bmi, which I would assume is the trifecta of overeating, little activity, and slower metabolism. At least that is my personal experience in going from overweight to healthy bmi. Really not surprising that people that eat less have lower bmi and higher metabolism than people that eat more with a slower metabolism but who are more active.
- marifjeren 4y ago
  Of course it's no surprise that people who eat less weigh less. The surprise, I think, is that people who are underweight are relatively sedentary. Maybe this is not that much of a surprise either though? I wonder how much of this has to do with muscle. BMI infamously ignores muscle mass. An interesting followup would be whether people with low body fat % are sedentary. My guess is that they aren't. Side note: maybe there is a disparate importance of "Calories In" vs "Calories Out" for people who are under/over weight. Maybe underweight people should focus on exercise more, and overweight people should focus on eating less?
  - rpmisms 4y ago
    I am mostly sedentary, and maintain body fat below 10%. It's mainly genetics, and probably 20% diet.
    - sovnade 4y ago
      and on top of that, it looks like there's other factors of diet than just choosing what to eat - it sounds like some people are just less hungry for indefinite reasons. genetics, gut biome, etc all probably play a part.
    - gamblor956 4y ago
      Sub-10% body fat is underwear model territory. At that low level of fat, every muscle is well-defined, no matter how small. A lot of guys severely underestimate their body fat %. Sub 10% generally isn't possible without heavy dieting unless you're still going through puberty; genetics has nothing to do with it.
deleted 4y ago
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ianbutler 4y ago
Does this breakdown when you gain weight? Like when I was 20 I weighed 180lbs of solid muscle and was always like a furnace. Then I slipped a disk and now at 28 I'm lucky if I hover around 240 (I've actually been back lifting for the last 2.5 months and feel pretty good) but I definitely feel like I run colder in general now that I'm overweight.
- FollowingTheDao 4y ago
  Gaining muscle mass will often lead to a quick onset of obesity once you stop lifting.
  - frostwarrior 4y ago
    Yes but this looks more like habit disruption more than "biologically gaining weight somehow". People that lift often eat more. But mostly protein, and stimulating muscle every day makes sure it will get developed and consume more calories to maintain itself. If you stop lifting altogether, not only muscle mass stops growing but also starts to shrink. If you eat the same, you will gain weight faster and with less food than before.
  - pc86 4y ago
    Nonsense. What I mean is, the fact that you have muscle mass and stop lifting is not what's going to lead to "a quick onset of obesity." What leads to weight gain is still eating like you're lifting when you're not. If you adjust your caloric intake to account for your new level of caloric expenditure, you will not gain weight, although you will likely see unfavorable body composition changes.
    - FollowingTheDao 4y ago
      > What leads to weight gain is still eating like you're lifting when you're not. Yeah, that's what I meant. So it is not nonsense.
      - atom-morgan 4y ago
giraffe_lady 4y ago
If I were playing a game of trying to extrapolate HN titles by the comment sections, my guess for this one would be "Ask HN: What's your BMI and what does that say about you"
- FollowingTheDao 4y ago
  Right? I was hoping more people would be thinking about the genetic aspect of this and how we need to stop telling people there is that "one diet" everyone should follow.
  - whatshisface 4y ago
    To be fair, the "CICO isn't the whole story" vs. "how can there be anything more to dieting than the diet you choose" debate is also a stereotypical HN favorite.
- marifjeren 4y ago
  Thank you for asking. My BMI is 31 and it's because I eat too much.
- the_only_law 4y ago
  Instead we get boring meta comments.
  - giraffe_lady 4y ago
    I'm only myself of course but to me, "why did so many people read this as an invitation to share personal health details with strangers in public" is actually a pretty interesting question. Sorry it was boring to you.
    - the_only_law 4y ago
      You made a sarcastic dismissal of other people's comments, as did I. If you were truly interested in the question you posted, You could have just explicitly asked.
daxfohl 4y ago
Curious if there is a difference between those who are lean and wiry, and those who are just skinny.
- stephenitis 4y ago
  What is the difference?
  - rootusrootus 4y ago
    Lots of thin people look good and thin wearing clothes, but if you could see their body you'd find they are mostly made of flab anyway. Colloquially referred to as skinny fat. Very little muscle.
jeffbee 4y ago
I wonder how they screened out people with eating disorders. It's not like you can just ask them, because part of the disorder is hiding the disorder.
sk8terboi 4y ago
inglor_cz 4y ago
I know a girl who weighs about 100 lbs soaking wet. Very slim, elfish type. She also has very hot hands and she says that after eating a big meal, she feels super hot. I asked her if it was measurable and it actually was, she can go to almost 38 degrees Celsius while completely healthy.
- aantix 4y ago
  I feel like I've seen a documentary about Kobayashi, the famous professional eater? He was sweating after eating mounds of food. And he had ripped abs.
csours 4y ago
Hunger is mediated by a bunch of hormones and you can test for some of those, but there is no test for the feeling of hunger. As a comparison, it is famously very hard for doctors to understand pain; it is also difficult for patients to communicate about pain. The feeling of hunger is not comparable between people. Hunger is driven by multiple sensations (blood sugar, stomach stretch, hormone levels) and by cognitive behaviors (it's lunchtime, it's a feast day) and psychological conditioning (advertising). People have relationships with, and expectations about food. The response to hunger is learned. It is driven by culture - for instance it is 'manly' to eat a large steak and loaded baked potato where I'm from; many times the smaller cuts of steak have either a woman's name or some feminine aspect. Scientists use Occam's Razor to find the most probable cause for some effect, and people in general want to find something simple to blame. I think the obesity epidemic has many causes, and it is particularly hard to understand because researchers have only lately begun to take hunger seriously. It is easy to say "Diet and Exercise" but losing body fat means that you must continuously make choices that decrease your comfort in some way - eating fewer highly rewarding foods, maintaining a state of hunger, increasing activity level. Those choices are difficult, and they are different for everyone. I believe there are many consequences of the difficulty in measuring and tracking hunger. I think that many people (including doctors and researchers and HN users) want to be able to change one thing or add one drug and suddenly solve the obesity epidemic. I think it makes it hard for doctors to talk to patients. It makes it hard for people to understand what their body is doing.
- convexfunction 4y ago
  > losing body fat means that you must continuously make choices that decrease your comfort in some way - eating fewer highly rewarding foods, maintaining a state of hunger, increasing activity level Not necessarily! I've successfully lost a lot of body fat (~50 pounds over the last 18 months) by deliberately changing my diet to eat more foods (that I like) that are lower in energy density than what I was eating before -- fruits and veggies, lean meats, etc. I do end up eating fewer stereotypically highly rewarding foods, but that's because I'm already full of other highly rewarding-to-me foods and don't feel like having a treat or a huge fast food meal or whatever. And I'm certainly not tolerating frequent hunger!
dilap 4y ago
There's a really interesting study they did with pigs. They fed pigs four different diets that had the same amount of calories, but varying ratios of n3/n6 fats. The pigs with high n6/n3 ratio ended up much fatter and less muscular than the pigs eating a 1-1 ratio diet. It's a very neat demonstration that "all that matters is calories" is not true; your metabolism, and thus how you use the calories, is influenced by the kinds of calories you are eating. Well, at least if you are a pig. But it seems likely the same holds true in humans, though AFAIK no one has yet tried to do a similar controlled trial in humans. But there's lots of assocational evidence that lines up in the same direction -- e.g., in America we've been getting fatter pretty much in-lock step with increasing consumption of n6 fats & there is a correlation between body-fat composition (which itself follows fat composition from the diet) and obesity. So, in the light of the above, my #1 weight loss tip is: eat fewer n6 fats. (In practice, this means avoiding most prepared processed foodes and being extremely selective if eating out (since restaurants tend to go crazy using vegetable oil as a cooking fat, which is super high in n6 fats).) The pigs study: https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/n6n3-pufa-ratio-is-involved-in-regulating-lipid-metabolism-and-inflammation-in-pigs/5EA34EC0D6F177F4C742F409DED4DBA5# https://www.cambridge.org/core/journals/british-journal-of-n...
- wowokay 4y ago
  That’s very interesting. I’m curious how it could relate to humans. Not to say it can’t be 1:1, but there are mental aspects that can effect human hunger and I’d be interested in research around that. For example someone who eats a lot but falls into a depression might slow eating considerably (or eat more depending on the person) it’s not to far fetched to consider the possibility of mind state altering medication that could stimulate the brain causing less or more hungry.
  - dilap 4y ago
    Absolutely, the mental aspects of hunger are huge, as anyone who has ever had the munchies (super hungry) or taken adderall (super not hungry) can attest. In fact, n6 fats may also promote hunger, via increasing endocannabinoid production. Here's a study I just found in mice: https://pubmed.ncbi.nlm.nih.gov/24081493/ https://pubmed.ncbi.nlm.nih.gov/24081493/ Again just an animal model, but certainly suggestive...
marifjeren 4y ago
"people with low BMI" seems like it refers to a large group of healthy people, but it actually refers to folks who are underweight. In China, that's like 1 in 10 people. In the USA it's closer to 1 in 50. I wonder what kind of genetics and behavior you have to have to be underweight in the USA.
- ErikAugust 4y ago
  Are 1 in 50 people in the US (ab)users of uppers? That could account for some of it.
  - marifjeren 4y ago
    Hmm yeah. Uppers, SSRIs, nicotine (if that's not already considered an 'upper'), ...
  - s1artibartfast 4y ago
    Also anorexia and other Medical comorbidities. A Many cancer patients have trouble keeping weight too
- chrchr 4y ago
  Also note that the subjects of this study were found to have subclinical hyperthyroidism. It’s an interesting study for what it tells us about metabolism, but the study subjects are probably not a model for health.
- deleted 4y ago
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Terretta 4y ago
Yes, and, about 8 minutes of true HIIT* at least 3 days a week for 6 weeks is proven to adjust your metabolic run level. Graph your weight. After 6 weeks of HIIT, you'll see weight really shed because you're not burning calories during exercise but 24/7, and because of that metabolic shift, the weight will continue to shed for months even if you stop HIIT. * HIIT is High Intensity Interval Training. It's a technical term, doesn't mean "oooh, that was intense". It means exercise at level that forces your body into using different metabolic mechanisms to fuel your effort. Initially it will probably make you feel ill. If you aren't used to it, and are doing it right, you will probably feel nauseous after the effort. Your aim is expending energy about 4 minutes above your VO2Max, doing anaerobic exercise. In a 4 - 8 minute routine called Tabata intervals** you can do: - 2 minute warmup to hit your second highest heart rate band (probably 125 - 135), then - 4 one minute intervals at max heart rate, generally 30 - 45 seconds "on" and 15 - 30 seconds recovery, four times in a row, followed by - 2 minutes cooldown. You can probably not hit these heart rates on foot or on normal exercise machines, you probably need a climber, rower, or elliptical (in that order of 'kicks your ass'). ** For iOS, try the app "Seconds Pro" which offers brilliant timer routines for loops within loops. EDIT TO ADD ANECDATA GRAPH: Here is my personal graph in 2015 and 2016 when I tried this in my mid-40s to get rid of the 30 lbs gain that happened after I hit 40 with a corresponding metabolic slowdown: https://i.imgur.com/pvbvoMy.jpg https://i.imgur.com/pvbvoMy.jpg I bought a Nokia scale about a month into HIIT in late spring, and stopped HIIT a couple weeks later. After stopping, dropped 10 lbs from early summer through the fall. Over winter, began to gain. Did HIIT again in spring of 2016 for six more weeks. Stopped when weight started shedding, dropped another 10 lbs. Finally, did one last cycle in 2017, dropped another 10 lbs. Overall graph from 2015 to 2021 (stopped bothering with the scale because was steady state): https://i.imgur.com/U6U7HrH.jpg https://i.imgur.com/U6U7HrH.jpg Haven't done HIIT since 2017, no purposeful exercise except for a few weeks of swimming in 2018. The three rounds of HIIT seem to have adjusted me back to my high school weight/metabolism balance. WARNING: These heart rate numbers are examples, see your doctor. Anerobic exercise and heart rate in your max heart rate band are potentially dangerous.
- zeroonetwothree 4y ago
  I actually tried this and it didn’t work for me. My weight stayed the same. Maybe my body is just hopeless. Is there actual evidence that this is generally effective?
throwawaymanbot 4y ago
99_00 4y ago
>looked at individuals with a very low BMI Using this study for general weight loss advice doesn't make sense because they are looking at outliers.
- newaccount2021 4y ago
drakonka 4y ago
I wish the "running hot" part was true for me. I feel cold so easily, to the point that I had to get myself checked out this year since my toes would go numb at the slightest chill. The hunger thing rings true, though. I often just forget to eat and end up eating one meal a day or maybe a meal and a snack. Then again, on other days I might snack through the whole day. It seems to balance out though; after a day of frequent eating usually come a couple of those totally-forgetting-to-eat days.
- q1w2 4y ago
  Diabetic?
  - drakonka 4y ago
    Nope; they didn't find anything wrong at all luckily (aside from slightly lower blood flow in my right leg that didn't lead to any cause for concern after more investigation). Just said it happens for some people, especially at lower bf%.
- seabrookmx 4y ago
  That sounds like Raynaud's.
  - drakonka 4y ago
    I think that was one of the avenues they considered, but ultimately they didn't come up with any particular diagnosis and told me not to worry about it since they ruled out the obvious dangerous causes.
Markoff 4y ago
I have currently exactly 20.0 BMI (1-3kg under what I consider my optimal weight), I don't really think I'm less hungry, more like I have better self control, obviously if I ate everything I like all the time I could easily gain 10 or more kg (I'm right now 11 kg away from my record weight), but my approach is when I reach certain weight I start limiting my intake to not go over and stay on my optimal target range. Also you can get used to feel hunger, I think most of the people in developed countries eat so much and so often they don't even experience feeling of hunger. Plus if you get used to smaller portions it's also easier to fill your shrunk stomach with smaller portions, it's about what your body is used to, it's all about self control. When I started to travel around Asia I weighted 88kg (my max), after year of traveling, lot of walking/hiking when I found new job in China I had 68kg when I liked like skeleton from concentration camp, now I am on my optimal weight exactly in middle between.
newaccount2021 4y ago
CJefferson 4y ago
I think the hungry bit is often under-discussed. I lost 75kg over 3 years, then put exactly 75kg back on over the 4 years after that. While losing weight, and keeping it off (for about 6 months), I was hungry all the time, every day. I hoped that my body would eventually "get used" to the new standard, but in the end (not conciously), I gave up -- it was too mentally tiring to be hungry whenever I was awake. I'm sure lots of it was a combination of physical and psycological -- I could eat lots of raw vegetables and not want to eat another carrot -- that wouldn't stop me eating something fatty/sugary.
- ripply 4y ago
  When I lost 13kg I had the same problem, I put it all back on immediately - I had an insatiable hunger after losing the weight. I ended up losing it all over again 6ish months later but this time I was able to keep it off because I didn’t have the hunger. The only difference was I lost it doing keto for the last month and I ate way healthier. I also run very hot and have a normal BMI now.
  - time0ut 4y ago
    I lost 16kg by being more active and careful with eating then got stuck. Then I switched to keto and lost another 14kg. Sticking to a keto diet was very hard. I quit after a few months and slowly gained 15kg back.
- jacamera 4y ago
  Did you ever try fasting for an extended period of time during any of that? I've never gone more than ~48 hours but from what I've watched and read, people seem to stop feeling hungry after say four or five days. I wonder if that could maybe act as a sort of hard reset for the constant feeling of hunger you experienced.
  - BlargMcLarg 4y ago
    Not a hard reset but my experience with a 72 hour fast has definitely been not feeling hungry, and the moment of eating a lot again restarted the entire thing. Feels like it is much easier to learn to eat a lot rather than eat very little.
tunap 4y ago
Anecdote: My temp has been averaging 96.7 throughout the Covid testings, I sweat more than most when awake and also when I sleep. I most often eat a hearty breakfast and am always grazing on bananas, granola, nuts, jerky... and there is always room for a honey bun or a chunk of chocolate, too. I don't eat lunch and forget / forego(too close to bedtime) dinner often enough. I keep my calories in line with my activities: More physical, more calories / Slow days, I don't get hungry and forget, or forego. And yeah, I'm active in work & play... use it or lose it is a critical component in my 2nd life(1). (1) “We all have two lives, the second life begins when we realize we only have one.” ― Confucius
mensetmanusman 4y ago
My mother moved in so we could care for her. I walked with her daily for over a year and she lost a pound per week with no diet change (~50lb). Winter/sprain made her seditary again then her body re-equilibriums right back in about 3 months.
dghughes 4y ago
My weight was a consistent 150 pounds since I was 14 years old. I joked to myself I was a robot since it was incredibly consistent for decades. I would often go entire days without eating. My family says as a kid or teen I would always cover my food with a napkin to hide what I had not eaten. Even as an adult I would rarely eat a fast food combo there would be half the burger and fries left over. I ate what I need even pop and chips but I ate a bit and when I wasn't hungry I stopped. In my mid 40s I felt lethargic bad and my face was puffy. Stranger still I was gaining weight and eating more than I ever did. I'd eat when I wasn't hungry which was a bizarre feeling. At the worst I was 190lbs the heaviest in my life. I was not a coffee or tea drinker but I got into energy drinks they made me feel normal. I went to the doctor and found out it was my thyroid I had hypothyroidism (under active). My Dad had it and now I did rare for men hypothyroidism more common in middle-aged women. My first synthroid pill felt like I'd drank ten energy drinks my skin was warm I felt clear of thought. But now it's stabilized and I think I'm on the downward slide again.
- bradser 4y ago
  If anyone has been on synthroid and it stops working for you, check with your doctor about switching to natural desiccated thyroid, made a big difference for me. Also see if avoiding goitrogenic foods works for you (like https://en.wikipedia.org/wiki/Cruciferous_vegetables); https://en.wikipedia.org/wiki/Cruciferous_vegetables); keeping a food diary for a few months proved to me how impactful they are for me, YMMV.
  - sorum 4y ago
    Would the interference from cruciferous vegetables show up on the bloodwork, i.e TSH levels and free T3, T4?
- winrid 4y ago
  Have you considered a diet like Keto? This may help your potentially insulin related issues.
winrid 4y ago
I'm one of these people. Always super hot after eating, especially carbs (which I now avoid). Hard to gain weight even at 28. I also almost always wake up covered in sweat and have to change cloths. So not all roses.
- donkarma 4y ago
  most people wake up sweaty
  - winrid 4y ago
    In the middle of the night? Having to change underwear and socks too? :P
  - TedShiller 4y ago
    Not me
  - doliveira 4y ago
    Not at all, and I live in Brazil of all places
kypro 4y ago
Something I think that contributes a lot to how much weight you hold naturally is how insulin sensitive you are. The more insulin sensitive you are the less weight you'll put on and there's a huge range between optimal insulin sensitivity, average, and diabetic. I also suspect (although I'm not an expert) the reason some people find it easier to lose weight while doing OMAD or keto isn't just because they're eating less, but because they're far more insulin sensitive and two of the best ways to increase insulin sensitivity is to fast or to eat less carbs. Another reason I believe this to be the case is because as I've aged I've noticed my friends are holding more weight despite little change their diets or physical activity. I'm sure some of this is related to a slowdown in their resting metabolic rate, but I also suspect it's got something to do with the fact that as people age they become less insulin sensitive on average -- especially if they don't eat well or eat too often. This is probably why as a kid you can eat a tub of icecream without putting on any weight, but as adult you would. It's not just that kids have higher metabolisms, but that they're more insulin sensitive and less likely to be diabetic or pre-diabetic. A question to ask here is why are people with low BMI's are less hungry? Could that be because they're metabolic healthier and their bodies are therefore better able to enter ketosis during periods without food? From personal experience with fasting and low carb diets I've experienced how significant it is when the body adjusts to burning fat as a primary fuel source. Although, you still feel hungry you don't feel like you need food. Similarly, you know when someone isn't metabolically adapted when they go too long without food because they become irritable and physically feel week.
- borroka 4y ago
  Basal metabolism does not seem to slow down until one is around 60 years old (recent NYT editorial on the Science publication https://www.nytimes.com/2021/08/12/health/metabolism-weight-aging.html https://www.nytimes.com/2021/08/12/health/metabolism-weight-...). There is heterogeneity, but still. Although our physiology is adaptable and we don't see daily or weekly wild weight swings with a few hundred calories up or down from maintenance, over weeks and months, 4-800 kcals of average daily surplus have very noticeable effects. And those are differences that can be had by working 2 days from office instead of 5 and getting into the habit of eating a cookie in the morning, while previously we just grabbed a black coffee and that was it. It is very easy to get into the "plus calories" territory. At the start of the pandemic, after a few weeks of working from home, many of my colleagues were 5-8 pounds heavier than they were before. And those pounds were not of muscle tissue.
balls187 4y ago
I eat all the time. I run hot. I also fat. I also think BMI is not a good measurement, not just because it says I'm morbidly obese, but also because it skews in favor of those with smaller frames for their height.
- notacoward 4y ago
  BMI seems to be one of those things that everyone in the relevant field knows is pretty damn bad, but no consensus has formed around anything better so they keep using it anyway. (I'm sure there are parallels to things in the software world - SQL comes quickly to mind - but that's a bit OT so I'll resist the temptation to explore that idea further.)
  - batty_alex 4y ago
    > but no consensus has formed around anything better BSA (DuBois method, usually) is more common (and considered a better measurement) outside of the states and is more accurate for folks outside of the "average" range. BMI is probably so popular because of how simple the formula is, compared to something like BSA
  - jobigoud 4y ago
    It's a good enough first approximation for the vast majority of people but because it's not perfect it is criticized by people with unfavorable numbers… which is the majority of people in certain societies.
    - notacoward 4y ago
- Macha 4y ago
  Personally my idle body temperature seems to scale with my weight. In my teens and early 20s I was on the underweight/healthy boundary and would really feel the cold. At my peak weight mid-covid I was mid-overweight BMI and the amount of sweating I did definitely increased. I've been losing it again since resuming a more normal level of exercise as covid restrictions ease, and I'm about back into the healthy zone which is losing it a lot faster than I put it on, so I'm curious if I notice any differences in perceived body heat as the trend continues.
sbf501 4y ago
Then why, as a chronically skinny person in my 50's, have I always been cold all the time? I've never felt like I "run hot".
brabel 4y ago
> they eat less food than those with a normal BMI. I found that really funny... did anyone really expected thin people do not eat less?
n8henrie 4y ago
There seems to be a lot of people in this thread conflating "feeling" hot with having an elevated metabolic rate, but I think these will be at best coincidentally concordant. Anecdote vs anecdote, my wife is always cold, but she's the naturally-thin-never-exercises one, whereas I am the ever-sweaty always-hot one that exercises regularly, and I'm usually overweight. Or, for example, patients with fever have an objectively elevated temperature by definition, and usually report chills (and ask for extra blankets). https://en.wikipedia.org/wiki/Doubly_labeled_water https://en.wikipedia.org/wiki/Doubly_labeled_water
convexfunction 4y ago
The article says the low BMI people ate "12% less food" (presumably that's measured in calories), though it may not be fully true that they're "less hungry". There's a very common tendency to assume that the satiety response is based on how many calories you eat, but perhaps unless you're actually starving, it mostly isn't! Primarily, you feel sated when your stomach is or has recently been full of food, but that's based more on the mechanical stretch of the food on the walls of your stomach than anything else (cf. laparoscopic bands and gastric bypass being incredibly effective at causing morbidly obese people to lose weight -- they're literally just making the stomach effectively smaller). There's certainly some truth to "running hotter" as well, at least in some of those subjects, but I'll bet that many of them are habitually eating a less energy-dense diet than heavier people, rather than feeling less hungry for any more innate reason. Dietary energy density has been investigated in lots of experimental and observational studies and found to do an overall very good job of predicting current BMI, long-term weight loss, and in metabolic ward experiments, ad libitum caloric intake.
- paulpauper 4y ago
  (cf. laproscopic bands and gastric bypass being incredibly effective at causing morbidly obese people to lose weight -- they're literally just making the stomach effectively smaller). They are not that effective. the weight loss is often not enough or the weight returns. Gastric bypass, which is a major operation, will seldom make a very obese person thin and the weight tends to slowly return.
  - convexfunction 4y ago
    It's all relative, innit? Compared to "telling people to diet and exercise", which is an almost perfectly ineffective intervention (as usually practiced at least), getting morbidly obese people to become "merely overweight" is huge and results in considerable improvements to life expectancy and morbidity. As summarized by Wikipedia, "median life-expectancy was 9.3 years longer for obese adults with diabetes who received bariatric surgery as compared to routine (non-surgical) care, whereas the life expectancy gain was 5.1 years longer for obese adults without diabetes", citing this meta-analysis: https://pubmed.ncbi.nlm.nih.gov/33965067/ https://pubmed.ncbi.nlm.nih.gov/33965067/
devoutsalsa 4y ago
Skinny people eat less. Shocker.
karol 4y ago
If you are an engineer you are intelligent enough to work out how your metabolism works and make changes. What would be a reason to stay fat?
- itsyaboi 4y ago
  Lack of will.
- 762236 4y ago
  We should all know our metabolic flexibility. But how do you know how much fat you can oxidize? It isn't easy to understand metabolism. I rely on a lactate test to figure it out.
- doliveira 4y ago
  Oh yeah, obviously fat people are fat because they don't understand thermodynamics. If you're an engineer, you should be smart enough to notice when you're making such a gross oversimplification
oblak 4y ago
As far as headlines go, this one is as spot on as they get. In my experience, this is certainly true. Ask my wife, she loves snuggling with me in the winters because well, I am a hot piece of ass. Literally.
conradev 4y ago
I vaguely remembered that the doubly-labeled water method was pretty neat, but I looked it up and it is as neat as I remember: https://en.wikipedia.org/wiki/Doubly_labeled_water#Mechanism_of_the_test https://en.wikipedia.org/wiki/Doubly_labeled_water#Mechanism... It's like plugging yourself into a power meter, except for cellular respiration
nonethewiser 4y ago
This title is clearly false. Some people are more active, and activity is a factor in BMI. Scientific studies shouldn't use clickbait titles.
TedShiller 4y ago
There is so much content saying “calorie counting doesn’t work!”, but actually it really does. If you eat less than you burn you will lose weight.
- jdminhbg 4y ago
  "Calorie counting" describes the input. This article is about the output. Maybe read it instead of giving a tautological but also wrong dismissal?
  - Macha 4y ago
    Calorie counting can also mean CICO, to be fair.
  - TedShiller 4y ago
    tautological — smart word! 100 HN brownie points
aeturnum 4y ago
I've been consistently underweight for the last 20 years of my life (BMI 17.9) and this describes my experience. I tend to be on the warm side, am not particularly active, generally have two or three meals a day and experience no urge to snack. Now that I'm getting towards 40 my "setpoint" weight seems to be creeping up and I may soon cross the line to be consistently on the low-end of "normal." I am still deciding how much energy (if any) I want to devote to keeping where I am now.
aantix 4y ago
Mounjaro (tirzepatide) and Wegovy (semaglutide) are the new class of weight loss drugs. And their results, crush anything before them. Once the price point of these medications come down, you're going to see a massive movement towards these solutions for long term weight loss. It's clear that motivation, accountability, peer pressure simply aren't enough for long term success in keeping weight off. By long term success, I mean decades of keeping the weight off. The abysmal dieting numbers prove this. The Neuroscience of Obesity | Peter Attia, M.D. & Stephan Guyenet, Ph.D. https://www.youtube.com/watch?v=9G3iLbQCIHI&t=7646s https://www.youtube.com/watch?v=9G3iLbQCIHI&t=7646s
- aantix 4y ago
  There's a startup opportunity here. We saw it with generic Viagra and Hims and Roman. Calibrate is the early mover in GLP-1 medications coupled with nutritional coaching, but there's a ton of room for competitors.
  - aantix 4y ago
    I've personally used Calibrate's platform. There's zero transparency to the medication approval process. If you ask a question, you will 1) receive an email 3-5 days later and 2) told that they generally don't provide status updates on medication. No transparency to the medication approval process, even though obtaining access to a GLP-1 medications for their patients, is a pillar of their business. Not even a simple "waiting to hear from insurance" on their dashboard. Super long delays and a snarky support staff to get basic medical questions answered. Here's their site. https://www.joincalibrate.com/ https://www.joincalibrate.com/ There's room for competitors.
rawoke083600 4y ago
>'run hotter' That is interesting ja. "generally(red-hearing word when speaking about science)" men I see don't get as cold as females in 'general' (PC/Wokeness be dammed - we talking about proper bro-science here) even though it's not unusual for females to carry more fat (waiting for internet gods to smite me), which is associated with with better heat isolation. With that in mind, I've noticed I am unusually immune to cold, like my fellow country folks will usually ask me if I know its winter (or some smart comment like that) cause I will be in shorts + t-shirts + sandals most of winter (South African Winters on average about (-2 To 8 Celsius) For anyone noticing this pattern of fashion (short+ sandals) yes I"m a white-male-Afrikaans-South-African. In winter when it's really really cold (Ragnarok levels) we will consider wearing socks with said sandals :) PS. As a interesting side note. I did do a 23andMe test and nothing out of the ordinary. Yes my ancestors are from Europe 91.2% I'm French-German decent.
analog31 4y ago
Something that has always puzzled me, if someone has a higher metabolic rate, where does the heat go? Their body temperature is the same.
stakkur 4y ago
BMI might be the most worthless metric of health ever invented.
StartupSales99 4y ago
[flagged]

"The investigators acknowledge some limitations on this research, including the fact that although they measured food intake, *they didn't measure what the participants were actually eating or their feelings of satiation or satiety*." This seems to directly contradict the title. EDIT: What food they are eating and how satiating that food may be is irrelevant. They did not measure the participants feelings of satiation or satiety. The title can't claim that the lower BMI people feel less hungry if you don't measure how hungry they feel.

burlesona 4y ago
I think they are saying the caloric intake was measured, but they didn’t distinguish between what kind of food the calories were coming from: > The participants were monitored for two weeks. Their food intake was measured with an isotope-based technique called the doubly-labeled water method, which assesses energy expenditure based on the difference between the turnover rates of hydrogen and oxygen in body water as a function of carbon dioxide production. Their physical activity was measured using an accelerometry-based motion detector. Also regarding the specific food choices: > The team is now expanding its research, including studies that include these measures. They also plan to look at genetic differences between normal weight and healthy underweight individuals. Preliminary analysis suggests single nucleotide polymorphisms in certain genes that might play a role.
- deleted 4y ago
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- _aavaa_ 4y ago
  I don't see how that has any impact on my point. title: "People with low BMI aren't more active, *they are just less hungry*, 'run hotter'" quotation: "they didn't measure what the participants were actually eating or *their feelings of satiation or satiety*" The title is factually untrue. You can't claim that people with lower BMI "are just less hungry" if you don't measure how hungry they feel.
  - phkahler 4y ago
    Depending what you eat, it's possible to basically eat all you want and still lose weight. One example is learning to love non-carb foods - eat all the antipasto salad and steak you like (expensive AF yes).
    - lazide 4y ago
      Which doesn’t refute the point the post you are replying to made at all.
    - FollowingTheDao 4y ago
      > One example is learning to love non-carb foods This could be true for some people, but not for everyone, which is where this research will lead. With all the love of science here why does no one think genetics matters when it comes to diet and health?
  - burlesona 4y ago
    OK, I see what you mean. However I would interpret the fact that people consistently ate less as strongly implying that they were less hungry in the first place. While one individual might go around hungry, in general people don’t experience hunger if they don’t have to. I think if they had substituted “eat less” for “are less hungry” the title would be fair.
- jstanley 4y ago
  Title says they are less hungry, researchers say they didn't measure feelings of satisfaction or satiety. I think that contradcits the title.
beanjuice 4y ago
Caloric intake is a measure of the energy we receive from food accurately, i believe they are referring more-so to an idea in a recent popular HN post, potatoes,[1] and which foods are more filling. It could be that there is error in what the less-eating participants happen to eat more-filling food, but not that the entire hypothesis would be incorrect. [1] https://dynomight.net/potato-diet/ https://dynomight.net/potato-diet/
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dontlistentome 4y ago
Totally agree with your point and find it really annoying. The original journal entry is titled: 'Higher than predicted resting energy expenditure and lower physical activity in healthy underweight Chinese adults.' and makes no such 'less hungry' claim. That appears to have been introduced from the 'cell press' journal/article promoting organization.
- FollowingTheDao 4y ago
  Did you read the full study?

arcanus 4y ago

"We expected to find that these people are really active and to have high activity metabolic rates matched by high food intakes," says corresponding author John Speakman, a professor at the Shenzhen Institutes of Advanced Technology in China and the University of Aberdeen in the UK. "It turns out that something rather different is going on. They had lower food intakes and lower activity, as well as surprisingly higher-than-expected resting metabolic rates linked to elevated levels of their thyroid hormones."

causi 4y ago
Makes me wonder, if thyroid disorders can cause obesity, can thyroid-modifying therapy or exogenous thyroid hormones treat obesity?
- tapland 4y ago
  I've been on and off thyroid medication since my early teens and bounced about 40 lbs up and down during it. My hormone issues were first found because I gained weight while being a competitive young athlete. I think the same range is pretty common for people with certain other medications. The whole dieting discussion, all nutrition advice, kcal in/out goes out the window when your metabolism is a black box. Afaik there still isn't any study showing that any dieting works long term? So if we want to fight an obesity epidemic more needs to be done than to shift blame to affected individuals.
- lazide 4y ago
  Common symptoms of thyroid disorders include obesity and/or excessive thinness (not anorexia per-se, but it can look like it), along with a cornocopia of other issues. Certain mental disorders (depression and anxiety) also highly correlate with obesity and/or underweight. A common treatment for ADHD (stimulants) often gets folks to a healthy weight that previously struggled on one side or the other. It’s a complex problem, with a lot of ever changing variables we have little insight into. Anecdotally, I know of several boomers that had serious thyroid issues likely tied to exposure to the Santa Susana Field Lab and Nevada nuclear testing. They were consuming milk and other products from areas contaminated by them at the right times. All the various plastics we’ve all been exposed to and other various chemicals are also likely doing something too. But also, the whole country has gotten dramatically more sedentary and media consumption focused, and the media keeps getting more and more anxiety inducing and alienating. As a country, we all need to ‘get out and touch some grass’ more too.

shay_ker 4y ago

Is this paper peer-reviewed?

gjsman-1000 4y ago
Does it matter? Many scientists in the know say that peer review is as good as a trashy spam filter these days. This isn't to say that it is absolutely useless, more that it is very overrated.
- BitwiseFool 4y ago
  I like to think of "peer review" in the same way as "peer code review". Just because someone looked at it and approved it doesn't mean that it is free of shortcomings and defects.
  - gjsman-1000 4y ago
    Not just "peer code review" from a good friend or someone working on the same project as you - a review from somebody who has a ton of stuff to review at once, in many different areas, and very limited time to do it.
    - lazide 4y ago
      Still better than something someone didn’t even bother trying to peer review, usually.
      - lvass 4y ago
        Not always. As academia becomes increasingly autocratic and contaminated by power, peer reviews become a marker for group-think, and placing relevance into peer review is a mechanism to empower the oligarchy and suppress technical dissidence, therefore anti-scientific.
    - HelloMcFly 4y ago
      I do peer review, and know colleagues that do as well. I'd say the median number of articles reviewed per person in a given year is 10. I don't claim to represent most reviewers, but I also don't think a presumption that reviewers primarily only have time to half-ass it is fair either.

gjsman-1000 4y ago

To be fully honest - I can relate to this. During my college years, I ate a full-size burger, potato fries, and soda every day for lunch for ~2 years. I never got fat and retained a healthy BMI, never crossing 200lbs despite being a 6'2" male - even though I almost never exercised and spent almost all day sitting working in the Math Lab. I did skip breakfast regularly so maybe that had something to do with it. My family on seeing the portion size (particularly the potato fries - think 3x a McDonalds large fries) thought it must be my brain consuming those calories or something.

sdfhdhjdw3 4y ago
> all day sitting working in the Math Lab What I tell people is that my powerful brain needs a lot of calories.
- deleted 4y ago
  [deleted]
mason55 4y ago
What did you eat for the rest of the day? Even if that meal was 2k calories, if you walked around campus a bit and ate moderate breakfasts and dinners then it’s not that crazy. It’s hard to get fat from one bad meal a day. What typically gets people is eating their daily needs via meals and then having high calorie snacks on top of that.
- the_only_law 4y ago
  Yeah it took me a while to realize why I could eat huge servings of the worst fatty, carb filled, sugary, etc. foods available and not gain weight. Then I noticed, that despite looking like a large meal, the calories weren't that high.
corrral 4y ago
4k+ per day of junk food from ages ~15-20. Then I had to knock it off because I stopped being able to do that while staying trim (got fat fast, and I really was trim before). Which is probably just as well because that wasn't healthy anyway. Dunno where it was all going. I wasn't really getting much bigger or taller for most of that span.

FollowingTheDao 4y ago

My family has Sami heritage, we run cold. My average body temp is 96.8 degrees. We also have trouble with hyperlipidemia, obesity, and early heart disease. So the genetics of all of this will be interesting. I have managed to avoid my family curse by eating pretty much only fish and game meat, like a Sami. And I do not eat much. It was the only diet that would raise my HDL.

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sgt 4y ago
Samis are also pretty small people. Almost like elves. That can actually be an advantage for longevity in some ways.
- FollowingTheDao 4y ago
  Yeah, we are all short stature as well. If fact, my older brother was given growth hormones as a young child because he was not "growing as expected". Idiots. All Inuit populations are shorter on average.
  - sgt 4y ago
    That's terrible! Hope they put an end to that.
giantg2 4y ago
I'm surprised how little is said about traditional diets. It's like everyone has to have the same numbers, diet, etc. If they don't, then it's automatically statins or bust.
- FollowingTheDao 4y ago
  Yes, but "traditional diets" for who? An Inuit? A Mediterranean farmer? A Sri Lankin Indian? Our traditional diets changes our genetics, so who you are will determine what is healthy for you. I agree with the statin. They tried to force them on me. I took a look at my genetics, changes my diet accordingly, and LDL and HDL reversed in three weeks and I have the blood work to prove it.

2OEH8eoCRo0 4y ago

I've always been told that I'm a "furnace" but I don't think that I'm less hungry. BMI of 19.5

toomuchtodo 4y ago
What's really needed is a statistical analysis such that 23andme would do, where you can take a matrix of people and their SNPs via genotyping, and then compare that to measured BMRs (basal metabolic rates). The switch that controls this is either genetic, gut flora, or a combination of the two. This leads me to believe the treatment will be either CRISPR or gut flora protocols (similar to how fecal transplants have altered the BMI state of the recipient [1]). [1] https://www.google.com/search?q=fecal+transplant+bmi https://www.google.com/search?q=fecal+transplant+bmi
- FollowingTheDao 4y ago
  ...with a focus on Mitochondrial Genetics. Regarding the gut, should probably take a peek at FUT2 genetics: https://www.sciencedirect.com/science/article/pii/S2352345X21000424 https://www.sciencedirect.com/science/article/pii/S2352345X2...

the_only_law 4y ago

Seems to line up with my experience, am always burning up (until I turn on the AC and freeze) Especially at night though I have to to jack the temperature down or I won't sleep. Also less hungry aligns pretty well. Unfortunately when I get hungry, it's normally "a little hungry) at akward spread out intervals. I probably feel most hungry after midnight but never eat then because well, I have to sleep soon. I've tried to put on weight before, but I could never stomach massive calories dense meals, without horrific nausea and discomfort.

sleepydog 4y ago
If you run hotter, wouldn't you feel less hot? Since your normal temperature would be that much higher than the ambient temperature. At least, when I have a fever I feel cold, even though I'm hot.
- JumpCrisscross 4y ago
  Speaking anecdotally, my body temperature tends to run above average and I have a body that is shit at throwing off heat. I have dark skin yet still managed to get sun stroke earlier this week in the Mediterranean because my biology prefers me lightheaded than sweating. Morning run in the snow and t-shirt, on the other hand? Easy peasy.
- JacobThreeThree 4y ago
  It seems like the study used metabolic rate (energy/time unit) and thyroid activity, not body temperature. That being said, metabolic rate probably correlates with body temperature, but that's not clear. What's interesting is that these people kept a high metabolic rate while doing less activity. It's almost like, if you rest more, your body will have the energy to increase its metabolic rate, or it could be totally physiological and it depends on the person.
- derefr 4y ago
  Feeling cold in a fever is a specific lie your brain tells your body, to trigger shivering, so that your skeletal muscle will help to heat you up even faster. Usually, when you're hot, you feel hot.

mrhands556 4y ago

I have a really low BMI but also I definitely run cold. My wife and I regularly fight over the thermostat.

carbadtraingood 4y ago
Do you run cold or feel cold? Because those are opposite. If you run hot, temperatures should feel relatively chilly. Like when you run a fever you feel cold.
- m0llusk 4y ago
  Fever is the immune system fighting infection. The better comparison is to light exercise which increases temperature and perceived temperature. Perceived internal temperature is in general most closely related to movement.
FollowingTheDao 4y ago
Feeling cold and having a low body temperature are not equivalent. Take your temperature as soon as you wake up for a week to know your normal resting temperature.

sudden_dystopia 4y ago

The study was underweight bmi vs healthy bmi. Nothing about overweight bmi, which I would assume is the trifecta of overeating, little activity, and slower metabolism. At least that is my personal experience in going from overweight to healthy bmi. Really not surprising that people that eat less have lower bmi and higher metabolism than people that eat more with a slower metabolism but who are more active.

marifjeren 4y ago
Of course it's no surprise that people who eat less weigh less. The surprise, I think, is that people who are underweight are relatively sedentary. Maybe this is not that much of a surprise either though? I wonder how much of this has to do with muscle. BMI infamously ignores muscle mass. An interesting followup would be whether people with low body fat % are sedentary. My guess is that they aren't. Side note: maybe there is a disparate importance of "Calories In" vs "Calories Out" for people who are under/over weight. Maybe underweight people should focus on exercise more, and overweight people should focus on eating less?
- rpmisms 4y ago
  I am mostly sedentary, and maintain body fat below 10%. It's mainly genetics, and probably 20% diet.
  - sovnade 4y ago
    and on top of that, it looks like there's other factors of diet than just choosing what to eat - it sounds like some people are just less hungry for indefinite reasons. genetics, gut biome, etc all probably play a part.
  - gamblor956 4y ago
    Sub-10% body fat is underwear model territory. At that low level of fat, every muscle is well-defined, no matter how small. A lot of guys severely underestimate their body fat %. Sub 10% generally isn't possible without heavy dieting unless you're still going through puberty; genetics has nothing to do with it.

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[deleted]

ianbutler 4y ago

Does this breakdown when you gain weight? Like when I was 20 I weighed 180lbs of solid muscle and was always like a furnace. Then I slipped a disk and now at 28 I'm lucky if I hover around 240 (I've actually been back lifting for the last 2.5 months and feel pretty good) but I definitely feel like I run colder in general now that I'm overweight.

FollowingTheDao 4y ago
Gaining muscle mass will often lead to a quick onset of obesity once you stop lifting.
- frostwarrior 4y ago
  Yes but this looks more like habit disruption more than "biologically gaining weight somehow". People that lift often eat more. But mostly protein, and stimulating muscle every day makes sure it will get developed and consume more calories to maintain itself. If you stop lifting altogether, not only muscle mass stops growing but also starts to shrink. If you eat the same, you will gain weight faster and with less food than before.
- pc86 4y ago
  Nonsense. What I mean is, the fact that you have muscle mass and stop lifting is not what's going to lead to "a quick onset of obesity." What leads to weight gain is still eating like you're lifting when you're not. If you adjust your caloric intake to account for your new level of caloric expenditure, you will not gain weight, although you will likely see unfavorable body composition changes.
  - FollowingTheDao 4y ago
    > What leads to weight gain is still eating like you're lifting when you're not. Yeah, that's what I meant. So it is not nonsense.
    - atom-morgan 4y ago

giraffe_lady 4y ago

If I were playing a game of trying to extrapolate HN titles by the comment sections, my guess for this one would be "Ask HN: What's your BMI and what does that say about you"

FollowingTheDao 4y ago
Right? I was hoping more people would be thinking about the genetic aspect of this and how we need to stop telling people there is that "one diet" everyone should follow.
- whatshisface 4y ago
  To be fair, the "CICO isn't the whole story" vs. "how can there be anything more to dieting than the diet you choose" debate is also a stereotypical HN favorite.
marifjeren 4y ago
Thank you for asking. My BMI is 31 and it's because I eat too much.
the_only_law 4y ago
Instead we get boring meta comments.
- giraffe_lady 4y ago
  I'm only myself of course but to me, "why did so many people read this as an invitation to share personal health details with strangers in public" is actually a pretty interesting question. Sorry it was boring to you.
  - the_only_law 4y ago
    You made a sarcastic dismissal of other people's comments, as did I. If you were truly interested in the question you posted, You could have just explicitly asked.

daxfohl 4y ago

Curious if there is a difference between those who are lean and wiry, and those who are just skinny.

stephenitis 4y ago
What is the difference?
- rootusrootus 4y ago
  Lots of thin people look good and thin wearing clothes, but if you could see their body you'd find they are mostly made of flab anyway. Colloquially referred to as skinny fat. Very little muscle.

jeffbee 4y ago

I wonder how they screened out people with eating disorders. It's not like you can just ask them, because part of the disorder is hiding the disorder.

sk8terboi 4y ago

inglor_cz 4y ago

I know a girl who weighs about 100 lbs soaking wet. Very slim, elfish type. She also has very hot hands and she says that after eating a big meal, she feels super hot. I asked her if it was measurable and it actually was, she can go to almost 38 degrees Celsius while completely healthy.

aantix 4y ago
I feel like I've seen a documentary about Kobayashi, the famous professional eater? He was sweating after eating mounds of food. And he had ripped abs.

csours 4y ago

Hunger is mediated by a bunch of hormones and you can test for some of those, but there is no test for the feeling of hunger. As a comparison, it is famously very hard for doctors to understand pain; it is also difficult for patients to communicate about pain. The feeling of hunger is not comparable between people. Hunger is driven by multiple sensations (blood sugar, stomach stretch, hormone levels) and by cognitive behaviors (it's lunchtime, it's a feast day) and psychological conditioning (advertising). People have relationships with, and expectations about food. The response to hunger is learned. It is driven by culture - for instance it is 'manly' to eat a large steak and loaded baked potato where I'm from; many times the smaller cuts of steak have either a woman's name or some feminine aspect. Scientists use Occam's Razor to find the most probable cause for some effect, and people in general want to find something simple to blame. I think the obesity epidemic has many causes, and it is particularly hard to understand because researchers have only lately begun to take hunger seriously. It is easy to say "Diet and Exercise" but losing body fat means that you must continuously make choices that decrease your comfort in some way - eating fewer highly rewarding foods, maintaining a state of hunger, increasing activity level. Those choices are difficult, and they are different for everyone. I believe there are many consequences of the difficulty in measuring and tracking hunger. I think that many people (including doctors and researchers and HN users) want to be able to change one thing or add one drug and suddenly solve the obesity epidemic. I think it makes it hard for doctors to talk to patients. It makes it hard for people to understand what their body is doing.

convexfunction 4y ago
> losing body fat means that you must continuously make choices that decrease your comfort in some way - eating fewer highly rewarding foods, maintaining a state of hunger, increasing activity level Not necessarily! I've successfully lost a lot of body fat (~50 pounds over the last 18 months) by deliberately changing my diet to eat more foods (that I like) that are lower in energy density than what I was eating before -- fruits and veggies, lean meats, etc. I do end up eating fewer stereotypically highly rewarding foods, but that's because I'm already full of other highly rewarding-to-me foods and don't feel like having a treat or a huge fast food meal or whatever. And I'm certainly not tolerating frequent hunger!

dilap 4y ago

There's a really interesting study they did with pigs. They fed pigs four different diets that had the same amount of calories, but varying ratios of n3/n6 fats. The pigs with high n6/n3 ratio ended up much fatter and less muscular than the pigs eating a 1-1 ratio diet. It's a very neat demonstration that "all that matters is calories" is not true; your metabolism, and thus how you use the calories, is influenced by the kinds of calories you are eating. Well, at least if you are a pig. But it seems likely the same holds true in humans, though AFAIK no one has yet tried to do a similar controlled trial in humans. But there's lots of assocational evidence that lines up in the same direction -- e.g., in America we've been getting fatter pretty much in-lock step with increasing consumption of n6 fats & there is a correlation between body-fat composition (which itself follows fat composition from the diet) and obesity. So, in the light of the above, my #1 weight loss tip is: eat fewer n6 fats. (In practice, this means avoiding most prepared processed foodes and being extremely selective if eating out (since restaurants tend to go crazy using vegetable oil as a cooking fat, which is super high in n6 fats).) The pigs study: https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/n6n3-pufa-ratio-is-involved-in-regulating-lipid-metabolism-and-inflammation-in-pigs/5EA34EC0D6F177F4C742F409DED4DBA5# https://www.cambridge.org/core/journals/british-journal-of-n...

wowokay 4y ago
That’s very interesting. I’m curious how it could relate to humans. Not to say it can’t be 1:1, but there are mental aspects that can effect human hunger and I’d be interested in research around that. For example someone who eats a lot but falls into a depression might slow eating considerably (or eat more depending on the person) it’s not to far fetched to consider the possibility of mind state altering medication that could stimulate the brain causing less or more hungry.
- dilap 4y ago
  Absolutely, the mental aspects of hunger are huge, as anyone who has ever had the munchies (super hungry) or taken adderall (super not hungry) can attest. In fact, n6 fats may also promote hunger, via increasing endocannabinoid production. Here's a study I just found in mice: https://pubmed.ncbi.nlm.nih.gov/24081493/ https://pubmed.ncbi.nlm.nih.gov/24081493/ Again just an animal model, but certainly suggestive...

marifjeren 4y ago

"people with low BMI" seems like it refers to a large group of healthy people, but it actually refers to folks who are underweight. In China, that's like 1 in 10 people. In the USA it's closer to 1 in 50. I wonder what kind of genetics and behavior you have to have to be underweight in the USA.

ErikAugust 4y ago
Are 1 in 50 people in the US (ab)users of uppers? That could account for some of it.
- marifjeren 4y ago
  Hmm yeah. Uppers, SSRIs, nicotine (if that's not already considered an 'upper'), ...
- s1artibartfast 4y ago
  Also anorexia and other Medical comorbidities. A Many cancer patients have trouble keeping weight too
chrchr 4y ago
Also note that the subjects of this study were found to have subclinical hyperthyroidism. It’s an interesting study for what it tells us about metabolism, but the study subjects are probably not a model for health.
deleted 4y ago
[deleted]

Terretta 4y ago

Yes, and, about 8 minutes of true HIIT* at least 3 days a week for 6 weeks is proven to adjust your metabolic run level. Graph your weight. After 6 weeks of HIIT, you'll see weight really shed because you're not burning calories during exercise but 24/7, and because of that metabolic shift, the weight will continue to shed for months even if you stop HIIT. * HIIT is High Intensity Interval Training. It's a technical term, doesn't mean "oooh, that was intense". It means exercise at level that forces your body into using different metabolic mechanisms to fuel your effort. Initially it will probably make you feel ill. If you aren't used to it, and are doing it right, you will probably feel nauseous after the effort. Your aim is expending energy about 4 minutes above your VO2Max, doing anaerobic exercise. In a 4 - 8 minute routine called Tabata intervals** you can do: - 2 minute warmup to hit your second highest heart rate band (probably 125 - 135), then - 4 one minute intervals at max heart rate, generally 30 - 45 seconds "on" and 15 - 30 seconds recovery, four times in a row, followed by - 2 minutes cooldown. You can probably not hit these heart rates on foot or on normal exercise machines, you probably need a climber, rower, or elliptical (in that order of 'kicks your ass'). ** For iOS, try the app "Seconds Pro" which offers brilliant timer routines for loops within loops. EDIT TO ADD ANECDATA GRAPH: Here is my personal graph in 2015 and 2016 when I tried this in my mid-40s to get rid of the 30 lbs gain that happened after I hit 40 with a corresponding metabolic slowdown: https://i.imgur.com/pvbvoMy.jpg https://i.imgur.com/pvbvoMy.jpg I bought a Nokia scale about a month into HIIT in late spring, and stopped HIIT a couple weeks later. After stopping, dropped 10 lbs from early summer through the fall. Over winter, began to gain. Did HIIT again in spring of 2016 for six more weeks. Stopped when weight started shedding, dropped another 10 lbs. Finally, did one last cycle in 2017, dropped another 10 lbs. Overall graph from 2015 to 2021 (stopped bothering with the scale because was steady state): https://i.imgur.com/U6U7HrH.jpg https://i.imgur.com/U6U7HrH.jpg Haven't done HIIT since 2017, no purposeful exercise except for a few weeks of swimming in 2018. The three rounds of HIIT seem to have adjusted me back to my high school weight/metabolism balance. WARNING: These heart rate numbers are examples, see your doctor. Anerobic exercise and heart rate in your max heart rate band are potentially dangerous.

zeroonetwothree 4y ago
I actually tried this and it didn’t work for me. My weight stayed the same. Maybe my body is just hopeless. Is there actual evidence that this is generally effective?

throwawaymanbot 4y ago

99_00 4y ago

>looked at individuals with a very low BMI Using this study for general weight loss advice doesn't make sense because they are looking at outliers.

newaccount2021 4y ago

drakonka 4y ago

I wish the "running hot" part was true for me. I feel cold so easily, to the point that I had to get myself checked out this year since my toes would go numb at the slightest chill. The hunger thing rings true, though. I often just forget to eat and end up eating one meal a day or maybe a meal and a snack. Then again, on other days I might snack through the whole day. It seems to balance out though; after a day of frequent eating usually come a couple of those totally-forgetting-to-eat days.

q1w2 4y ago
Diabetic?
- drakonka 4y ago
  Nope; they didn't find anything wrong at all luckily (aside from slightly lower blood flow in my right leg that didn't lead to any cause for concern after more investigation). Just said it happens for some people, especially at lower bf%.
seabrookmx 4y ago
That sounds like Raynaud's.
- drakonka 4y ago
  I think that was one of the avenues they considered, but ultimately they didn't come up with any particular diagnosis and told me not to worry about it since they ruled out the obvious dangerous causes.

Markoff 4y ago

I have currently exactly 20.0 BMI (1-3kg under what I consider my optimal weight), I don't really think I'm less hungry, more like I have better self control, obviously if I ate everything I like all the time I could easily gain 10 or more kg (I'm right now 11 kg away from my record weight), but my approach is when I reach certain weight I start limiting my intake to not go over and stay on my optimal target range. Also you can get used to feel hunger, I think most of the people in developed countries eat so much and so often they don't even experience feeling of hunger. Plus if you get used to smaller portions it's also easier to fill your shrunk stomach with smaller portions, it's about what your body is used to, it's all about self control. When I started to travel around Asia I weighted 88kg (my max), after year of traveling, lot of walking/hiking when I found new job in China I had 68kg when I liked like skeleton from concentration camp, now I am on my optimal weight exactly in middle between.

newaccount2021 4y ago

CJefferson 4y ago

I think the hungry bit is often under-discussed. I lost 75kg over 3 years, then put exactly 75kg back on over the 4 years after that. While losing weight, and keeping it off (for about 6 months), I was hungry all the time, every day. I hoped that my body would eventually "get used" to the new standard, but in the end (not conciously), I gave up -- it was too mentally tiring to be hungry whenever I was awake. I'm sure lots of it was a combination of physical and psycological -- I could eat lots of raw vegetables and not want to eat another carrot -- that wouldn't stop me eating something fatty/sugary.

ripply 4y ago
When I lost 13kg I had the same problem, I put it all back on immediately - I had an insatiable hunger after losing the weight. I ended up losing it all over again 6ish months later but this time I was able to keep it off because I didn’t have the hunger. The only difference was I lost it doing keto for the last month and I ate way healthier. I also run very hot and have a normal BMI now.
- time0ut 4y ago
  I lost 16kg by being more active and careful with eating then got stuck. Then I switched to keto and lost another 14kg. Sticking to a keto diet was very hard. I quit after a few months and slowly gained 15kg back.
jacamera 4y ago
Did you ever try fasting for an extended period of time during any of that? I've never gone more than ~48 hours but from what I've watched and read, people seem to stop feeling hungry after say four or five days. I wonder if that could maybe act as a sort of hard reset for the constant feeling of hunger you experienced.
- BlargMcLarg 4y ago
  Not a hard reset but my experience with a 72 hour fast has definitely been not feeling hungry, and the moment of eating a lot again restarted the entire thing. Feels like it is much easier to learn to eat a lot rather than eat very little.

tunap 4y ago

Anecdote: My temp has been averaging 96.7 throughout the Covid testings, I sweat more than most when awake and also when I sleep. I most often eat a hearty breakfast and am always grazing on bananas, granola, nuts, jerky... and there is always room for a honey bun or a chunk of chocolate, too. I don't eat lunch and forget / forego(too close to bedtime) dinner often enough. I keep my calories in line with my activities: More physical, more calories / Slow days, I don't get hungry and forget, or forego. And yeah, I'm active in work & play... use it or lose it is a critical component in my 2nd life(1). (1) “We all have two lives, the second life begins when we realize we only have one.” ― Confucius

mensetmanusman 4y ago

My mother moved in so we could care for her. I walked with her daily for over a year and she lost a pound per week with no diet change (~50lb). Winter/sprain made her seditary again then her body re-equilibriums right back in about 3 months.

dghughes 4y ago

My weight was a consistent 150 pounds since I was 14 years old. I joked to myself I was a robot since it was incredibly consistent for decades. I would often go entire days without eating. My family says as a kid or teen I would always cover my food with a napkin to hide what I had not eaten. Even as an adult I would rarely eat a fast food combo there would be half the burger and fries left over. I ate what I need even pop and chips but I ate a bit and when I wasn't hungry I stopped. In my mid 40s I felt lethargic bad and my face was puffy. Stranger still I was gaining weight and eating more than I ever did. I'd eat when I wasn't hungry which was a bizarre feeling. At the worst I was 190lbs the heaviest in my life. I was not a coffee or tea drinker but I got into energy drinks they made me feel normal. I went to the doctor and found out it was my thyroid I had hypothyroidism (under active). My Dad had it and now I did rare for men hypothyroidism more common in middle-aged women. My first synthroid pill felt like I'd drank ten energy drinks my skin was warm I felt clear of thought. But now it's stabilized and I think I'm on the downward slide again.

bradser 4y ago
If anyone has been on synthroid and it stops working for you, check with your doctor about switching to natural desiccated thyroid, made a big difference for me. Also see if avoiding goitrogenic foods works for you (like https://en.wikipedia.org/wiki/Cruciferous_vegetables); https://en.wikipedia.org/wiki/Cruciferous_vegetables); keeping a food diary for a few months proved to me how impactful they are for me, YMMV.
- sorum 4y ago
  Would the interference from cruciferous vegetables show up on the bloodwork, i.e TSH levels and free T3, T4?
winrid 4y ago
Have you considered a diet like Keto? This may help your potentially insulin related issues.

winrid 4y ago

I'm one of these people. Always super hot after eating, especially carbs (which I now avoid). Hard to gain weight even at 28. I also almost always wake up covered in sweat and have to change cloths. So not all roses.

donkarma 4y ago
most people wake up sweaty
- winrid 4y ago
  In the middle of the night? Having to change underwear and socks too? :P
- TedShiller 4y ago
  Not me
- doliveira 4y ago
  Not at all, and I live in Brazil of all places

kypro 4y ago

Something I think that contributes a lot to how much weight you hold naturally is how insulin sensitive you are. The more insulin sensitive you are the less weight you'll put on and there's a huge range between optimal insulin sensitivity, average, and diabetic. I also suspect (although I'm not an expert) the reason some people find it easier to lose weight while doing OMAD or keto isn't just because they're eating less, but because they're far more insulin sensitive and two of the best ways to increase insulin sensitivity is to fast or to eat less carbs. Another reason I believe this to be the case is because as I've aged I've noticed my friends are holding more weight despite little change their diets or physical activity. I'm sure some of this is related to a slowdown in their resting metabolic rate, but I also suspect it's got something to do with the fact that as people age they become less insulin sensitive on average -- especially if they don't eat well or eat too often. This is probably why as a kid you can eat a tub of icecream without putting on any weight, but as adult you would. It's not just that kids have higher metabolisms, but that they're more insulin sensitive and less likely to be diabetic or pre-diabetic. A question to ask here is why are people with low BMI's are less hungry? Could that be because they're metabolic healthier and their bodies are therefore better able to enter ketosis during periods without food? From personal experience with fasting and low carb diets I've experienced how significant it is when the body adjusts to burning fat as a primary fuel source. Although, you still feel hungry you don't feel like you need food. Similarly, you know when someone isn't metabolically adapted when they go too long without food because they become irritable and physically feel week.

borroka 4y ago
Basal metabolism does not seem to slow down until one is around 60 years old (recent NYT editorial on the Science publication https://www.nytimes.com/2021/08/12/health/metabolism-weight-aging.html https://www.nytimes.com/2021/08/12/health/metabolism-weight-...). There is heterogeneity, but still. Although our physiology is adaptable and we don't see daily or weekly wild weight swings with a few hundred calories up or down from maintenance, over weeks and months, 4-800 kcals of average daily surplus have very noticeable effects. And those are differences that can be had by working 2 days from office instead of 5 and getting into the habit of eating a cookie in the morning, while previously we just grabbed a black coffee and that was it. It is very easy to get into the "plus calories" territory. At the start of the pandemic, after a few weeks of working from home, many of my colleagues were 5-8 pounds heavier than they were before. And those pounds were not of muscle tissue.

balls187 4y ago

I eat all the time. I run hot. I also fat. I also think BMI is not a good measurement, not just because it says I'm morbidly obese, but also because it skews in favor of those with smaller frames for their height.

notacoward 4y ago
BMI seems to be one of those things that everyone in the relevant field knows is pretty damn bad, but no consensus has formed around anything better so they keep using it anyway. (I'm sure there are parallels to things in the software world - SQL comes quickly to mind - but that's a bit OT so I'll resist the temptation to explore that idea further.)
- batty_alex 4y ago
  > but no consensus has formed around anything better BSA (DuBois method, usually) is more common (and considered a better measurement) outside of the states and is more accurate for folks outside of the "average" range. BMI is probably so popular because of how simple the formula is, compared to something like BSA
- jobigoud 4y ago
  It's a good enough first approximation for the vast majority of people but because it's not perfect it is criticized by people with unfavorable numbers… which is the majority of people in certain societies.
  - notacoward 4y ago
Macha 4y ago
Personally my idle body temperature seems to scale with my weight. In my teens and early 20s I was on the underweight/healthy boundary and would really feel the cold. At my peak weight mid-covid I was mid-overweight BMI and the amount of sweating I did definitely increased. I've been losing it again since resuming a more normal level of exercise as covid restrictions ease, and I'm about back into the healthy zone which is losing it a lot faster than I put it on, so I'm curious if I notice any differences in perceived body heat as the trend continues.

sbf501 4y ago

Then why, as a chronically skinny person in my 50's, have I always been cold all the time? I've never felt like I "run hot".

brabel 4y ago

> they eat less food than those with a normal BMI. I found that really funny... did anyone really expected thin people do not eat less?

n8henrie 4y ago

There seems to be a lot of people in this thread conflating "feeling" hot with having an elevated metabolic rate, but I think these will be at best coincidentally concordant. Anecdote vs anecdote, my wife is always cold, but she's the naturally-thin-never-exercises one, whereas I am the ever-sweaty always-hot one that exercises regularly, and I'm usually overweight. Or, for example, patients with fever have an objectively elevated temperature by definition, and usually report chills (and ask for extra blankets). https://en.wikipedia.org/wiki/Doubly_labeled_water https://en.wikipedia.org/wiki/Doubly_labeled_water

convexfunction 4y ago

The article says the low BMI people ate "12% less food" (presumably that's measured in calories), though it may not be fully true that they're "less hungry". There's a very common tendency to assume that the satiety response is based on how many calories you eat, but perhaps unless you're actually starving, it mostly isn't! Primarily, you feel sated when your stomach is or has recently been full of food, but that's based more on the mechanical stretch of the food on the walls of your stomach than anything else (cf. laparoscopic bands and gastric bypass being incredibly effective at causing morbidly obese people to lose weight -- they're literally just making the stomach effectively smaller). There's certainly some truth to "running hotter" as well, at least in some of those subjects, but I'll bet that many of them are habitually eating a less energy-dense diet than heavier people, rather than feeling less hungry for any more innate reason. Dietary energy density has been investigated in lots of experimental and observational studies and found to do an overall very good job of predicting current BMI, long-term weight loss, and in metabolic ward experiments, ad libitum caloric intake.

paulpauper 4y ago
(cf. laproscopic bands and gastric bypass being incredibly effective at causing morbidly obese people to lose weight -- they're literally just making the stomach effectively smaller). They are not that effective. the weight loss is often not enough or the weight returns. Gastric bypass, which is a major operation, will seldom make a very obese person thin and the weight tends to slowly return.
- convexfunction 4y ago
  It's all relative, innit? Compared to "telling people to diet and exercise", which is an almost perfectly ineffective intervention (as usually practiced at least), getting morbidly obese people to become "merely overweight" is huge and results in considerable improvements to life expectancy and morbidity. As summarized by Wikipedia, "median life-expectancy was 9.3 years longer for obese adults with diabetes who received bariatric surgery as compared to routine (non-surgical) care, whereas the life expectancy gain was 5.1 years longer for obese adults without diabetes", citing this meta-analysis: https://pubmed.ncbi.nlm.nih.gov/33965067/ https://pubmed.ncbi.nlm.nih.gov/33965067/

devoutsalsa 4y ago

Skinny people eat less. Shocker.

karol 4y ago

If you are an engineer you are intelligent enough to work out how your metabolism works and make changes. What would be a reason to stay fat?

itsyaboi 4y ago
Lack of will.
762236 4y ago
We should all know our metabolic flexibility. But how do you know how much fat you can oxidize? It isn't easy to understand metabolism. I rely on a lactate test to figure it out.
doliveira 4y ago
Oh yeah, obviously fat people are fat because they don't understand thermodynamics. If you're an engineer, you should be smart enough to notice when you're making such a gross oversimplification

oblak 4y ago

As far as headlines go, this one is as spot on as they get. In my experience, this is certainly true. Ask my wife, she loves snuggling with me in the winters because well, I am a hot piece of ass. Literally.

conradev 4y ago

I vaguely remembered that the doubly-labeled water method was pretty neat, but I looked it up and it is as neat as I remember: https://en.wikipedia.org/wiki/Doubly_labeled_water#Mechanism_of_the_test https://en.wikipedia.org/wiki/Doubly_labeled_water#Mechanism... It's like plugging yourself into a power meter, except for cellular respiration

nonethewiser 4y ago

This title is clearly false. Some people are more active, and activity is a factor in BMI. Scientific studies shouldn't use clickbait titles.

TedShiller 4y ago

There is so much content saying “calorie counting doesn’t work!”, but actually it really does. If you eat less than you burn you will lose weight.

jdminhbg 4y ago
"Calorie counting" describes the input. This article is about the output. Maybe read it instead of giving a tautological but also wrong dismissal?
- Macha 4y ago
  Calorie counting can also mean CICO, to be fair.
- TedShiller 4y ago
  tautological — smart word! 100 HN brownie points

aeturnum 4y ago

I've been consistently underweight for the last 20 years of my life (BMI 17.9) and this describes my experience. I tend to be on the warm side, am not particularly active, generally have two or three meals a day and experience no urge to snack. Now that I'm getting towards 40 my "setpoint" weight seems to be creeping up and I may soon cross the line to be consistently on the low-end of "normal." I am still deciding how much energy (if any) I want to devote to keeping where I am now.

aantix 4y ago

Mounjaro (tirzepatide) and Wegovy (semaglutide) are the new class of weight loss drugs. And their results, crush anything before them. Once the price point of these medications come down, you're going to see a massive movement towards these solutions for long term weight loss. It's clear that motivation, accountability, peer pressure simply aren't enough for long term success in keeping weight off. By long term success, I mean decades of keeping the weight off. The abysmal dieting numbers prove this. The Neuroscience of Obesity | Peter Attia, M.D. & Stephan Guyenet, Ph.D. https://www.youtube.com/watch?v=9G3iLbQCIHI&t=7646s https://www.youtube.com/watch?v=9G3iLbQCIHI&t=7646s

aantix 4y ago
There's a startup opportunity here. We saw it with generic Viagra and Hims and Roman. Calibrate is the early mover in GLP-1 medications coupled with nutritional coaching, but there's a ton of room for competitors.
- aantix 4y ago
  I've personally used Calibrate's platform. There's zero transparency to the medication approval process. If you ask a question, you will 1) receive an email 3-5 days later and 2) told that they generally don't provide status updates on medication. No transparency to the medication approval process, even though obtaining access to a GLP-1 medications for their patients, is a pillar of their business. Not even a simple "waiting to hear from insurance" on their dashboard. Super long delays and a snarky support staff to get basic medical questions answered. Here's their site. https://www.joincalibrate.com/ https://www.joincalibrate.com/ There's room for competitors.

rawoke083600 4y ago

>'run hotter' That is interesting ja. "generally(red-hearing word when speaking about science)" men I see don't get as cold as females in 'general' (PC/Wokeness be dammed - we talking about proper bro-science here) even though it's not unusual for females to carry more fat (waiting for internet gods to smite me), which is associated with with better heat isolation. With that in mind, I've noticed I am unusually immune to cold, like my fellow country folks will usually ask me if I know its winter (or some smart comment like that) cause I will be in shorts + t-shirts + sandals most of winter (South African Winters on average about (-2 To 8 Celsius) For anyone noticing this pattern of fashion (short+ sandals) yes I"m a white-male-Afrikaans-South-African. In winter when it's really really cold (Ragnarok levels) we will consider wearing socks with said sandals :) PS. As a interesting side note. I did do a 23andMe test and nothing out of the ordinary. Yes my ancestors are from Europe 91.2% I'm French-German decent.

analog31 4y ago

Something that has always puzzled me, if someone has a higher metabolic rate, where does the heat go? Their body temperature is the same.

stakkur 4y ago

BMI might be the most worthless metric of health ever invented.

StartupSales99 4y ago

[flagged]