10 ms·

Intermittent fasting associated with increased risk of early death

38 points by crhulls 4y ago

mtgentry 4y ago
“Among participant with three meals per day, a meal interval of ≤4.5 hours in two adjacent meals was associated with higher all-cause mortality.” So people who ate three meals a day ALSO fared poorly? Am I reading that right?
- pc86 4y ago
  Eating three meals with a shorter meal interval has higher all-cause mortality than eating three meals with a longer meal interval. It's not saying anything about 3 meals vs. any other number of meals.
- troydavis 4y ago
  Only those who had less than 4.5 hours between 2 of their 3 meals. The lowest hazard rate/lowest all-cause mortality was among those who ate 3 meals a day and had 4.5+ hours between them.
- VernorVintage 4y ago
  None of us are reading it right yet. We're not interpreting the "Hazard Ratios" - whatever those are. Until someone comes along and explains it (or uses chatGPT/bing to explain it), there's no point to form opinions about these results. In addition, we need to know what percentage of the people were doing fasting, in order to determine if the HRs are statistically significant. That claim a 95% confidence ratio, but is that true? If we're not able to do this kind of simple checkup on the data, we will just confuse us even more when we find another paper that adds even more naunce and complexity to the issue. That's how people become anti-science. Because we don't understand /this/ work, this work causes us cognitive dissonance. And because we don't understand this work, our dissonance is even worse next time. I hope a kind statistician comes along and help our thread about by explaining the numbers and what they really mean in terms of death risk and life expectancy.
VernorVintage 4y ago
Can someone interpret the Hazard Ratios for me? What is a HR of 1.3 or 1.8 actually saying?
- abecedarius 4y ago
  Good question: it turns out I didn't know there's a technical difference between "hazard ratio" and "relative risk". https://en.wikipedia.org/wiki/Hazard_ratio https://en.wikipedia.org/wiki/Hazard_ratio But the basic idea is that in the samples under the two different conditions, the ratio of the observed frequencies is 1.3 or 1.8. E.g. it'd be 1.8 if in the fasting sample they saw 3.6% bad outcome, while in the nonfasting sample they saw 2.0% bad outcome.
  - VernorVintage 4y ago
    Okay, wow so HR 1.8 literally does mean that fasters are nearly twice as likely to die over a given period as non-faster. But the death rate for fasters and nonfasters can still be pretty low, for example 2% a year vs 1% a year. Since the risk is low already, an individual might be indifferent to a 1% or 2% death rate - from an individual perspective the two are even statistically indistinguishable (they can't exactly die more than once!) Okay, I'm a little less freaked out by the seeming /doubling/ of death rate, however, it's still 2x increase in death rate. Still chilling! Now I suppose that if we assume the death rate is constant for everyone at all times - or use a more realistic actuarial curve - then we can even transform the HR factor into an average effect on lifespan for fasters vs nonfaster. Then we could say "ah, nonfasters will die on average 4 years sooner than nonfasters". I think that would help contextualize the numbers even better than relative death rates (which are hard for individuals to reason about). Are you familiar with how we might convert death HR into an expected lifespan delta for the average person? Would that analysis actually hold any meaningful truth?
    - abecedarius 4y ago
      > Are you familiar with how we might convert death HR into an expected lifespan delta for the average person? You'd have to integrate over lifespan using an actuarial table, I assume. This figure of 1.8 wasn't for all-cause mortality, but rather for heart-disease deaths among breakfast-skippers. I wouldn't worry (much) for a bunch of related reasons: - The more complexity you need to specify a statistic, the more evidence you need to overcome a presumption it's an artifact. (Some of this caveat shows up in how they report it ("multivariable-adjusted", "95% confidence interval"), but these frequentist-statistics methods don't really account for all the real-world reasons for doubt.) - This study was observational, not interventional. It's one study. Observational studies, particularly in epidemiology, particularly for diet, are often misleading. - What'd be the mechanism making skipping breakfast have this big an effect? There could well be a good answer to that, but it doesn't spring to mind for me. In other words, what was your prior on this hypothesis, before this paper? - I haven't read the paper beyond the abstract linked to, but https://news.ycombinator.com/item?id=34883541 https://news.ycombinator.com/item?id=34883541 lists some potential problems. - The process that brings a particular medical paper to your attention, unfortunately, is not much like one that optimizes for the most significant updates to the probability distribution you should have over hypotheses. Unless you have a much better news feed than most of us, anyway. I think of a result like this as a little bit of evidence to keep in mind as you learn more. It's not making me do anything different right now. That might seem harsh about a study involving "185,398 person-years of follow-up period" -- that must've taken a fuck-ton of work -- but it seems to be the world we're in.
jankyxenon 4y ago
The study period is from 1999 to 2014. IF wasn't a mainstream practice then - meaning that the bulk of people who try to eat healthy may have been targeting more meals in that period than recent years. Just a possible hypothesis.
- p1esk 4y ago
  I thought IF was more popular in the 90s than it is now.
mataug 4y ago
Associated !== Attributed https://en.wikipedia.org/wiki/Academy_of_Nutrition_and_Dietetics#Criticism_of_partnerships_with_food_companies https://en.wikipedia.org/wiki/Academy_of_Nutrition_and_Diete...
- unloco 4y ago
  Of course. I was wondering how eating less could cause death. That "academy" is sponsored by Wendy's and Coca-cola. The organization also publishes nutrition facts sheets for the general public, which food companies pay $20,000 to take part in writing the documents.[77] A list of these publications for the general public include: What's a Mom to Do: Healthy Eating Tips for Families sponsored by Wendy's.[78] Lamb: The Essence of Nutrient Rich Flavor sponsored by the Tri-Lamb Group.[79] Cocoa and Chocolate: Sweet News! sponsored by the Hershey Center for Health and Nutrition.[80] Eggs: A Good Choice for Moms-to-Be sponsored by the American Egg Board.[81] Adult Beverage Consumption: Making Responsible Drinking Choices sponsored by the Distilled Spirits Council.[82] This industry funding also gives food companies the ability to offer official educational seminars to teach dietitians how to advise their clients in a way that advances the interests of the food company. For instance, in a Coca-Cola sponsored seminar for dietitians, the speaker promoted free sugars consumption for children as a healthy choice.[83]"
icare_1er 4y ago
It's a bit like red wine, every week there's a new study proving the opposite of what the previous study said.
tqi 4y ago
They claiming a statistically significant hazard ratio within 1-6 years of a single survey response, that covers only the previous 24 hours? No other factors considered? This doesn't pass the smell test.
- deleted 4y ago
  [deleted]
irrational 4y ago
Maybe because those who are trying to diet are already obese?
- throwaway1777 4y ago
  A lot of people doing intermittent fasting are not obese. In fact a large portion of the people I know who do it are more athlete/biohacker types (I fall into this bucket myself)
- madeofpalk 4y ago
  I don't think intermittent fasting is 'weight loss dieting' In my limited personal experience, it's not obese people i see doing intermittent fasting - it's more like the keto crowd.
  - Kelteseth 4y ago
    My experience tells me the exact opposite. I lost more than 20kg thanks to IF. I would not have done it, if it would not mean I will lose weight.
    - exfatloss 4y ago
      Keto-crowd and weight-loss crowd have a massive overlap. If you get into keto for fat loss these days, you will almost certainly encounter IF ideas and will likely try some form yourself. I have.
- nequo 4y ago
  Rather unfortunately, the paper is behind a paywall but the results use this phrase: the multivariable-adjusted HRs for participants That suggests to me that they controlled for BMI or other proxies for obesity.
deleted 4y ago
[deleted]
rand0mx1 4y ago
Earlier, on HN I read that it improves lifespan and now it is associated with early death.
- bayesian_horse 4y ago
  Not the same thing... Also there can't be scientific evidence that anything improves lifespan.
  - kaczordon 4y ago
    Of course there can be evidence.
  - rileymat2 4y ago
    Can you speak more to "Also there can't be scientific evidence that anything improves lifespan." I am missing the subtlety, but I would think statistically with twin studies and controlled experiments you could?
    - bayesian_horse 4y ago
      There is always the difference between causation and association...
  - sokoloff 4y ago
    I think there’s ample evidence that seatbelts and airbags save lives, thereby improving lifespan as compared to the control (same number of car trips). Similarly, avoiding or ceasing of habitual smoking of cigarettes has ample evidence for lifespan improvement.
    - bayesian_horse 4y ago
      There is a fine distinction between scientific definitions of causality and association, incident rates and survival time, and other concepts.... Colloquially all of that is a lot easier to state.
GalenErso 4y ago
Am I wrong to have suspicions about the possibility that food conglomerates may have funded this study? I am not a conspiracy theorist, but with the number of dietary science that turned out to be wrong over time, I must be skeptical about every new study.
- LegitShady 4y ago
  if you have some kind of evidence to believe that, you wouldn't be wrong. But without that evidence, yes, you'd be wrong to have suspicions just based on disagreeing with the result.
- Calavar 4y ago
  > with the number of dietary science that turned out to be wrong over time, I must be skeptical about every new study. This I agree with. There is so much noise and so many confounding factors affecting the underlying data that you are bound to frequently get conflicting results. Compound this with the fact that studies with the most surprising (read: contrarian) results tend to get the most press, and you get an infinite see-saw in the literature. > Am I wrong to have suspicions about the possibility that food conglomerates may have funded this study? This I don't agree with. I think your model of more fasting equals less spending on food is overly simplicitic. The sort of health conscious people who are interested in IF tend to be wealthy and willing to spend on premium health related products. I'd wager that you can make a lot more money selling a few premium, organic, protein bars that you pitch as premium feel-full-for-12-hour-guaranteed products than you can by selling the same old breakfast cereals. Besides, Occam's razor. Intermittent fasting is not a subject where there is or ever has been an overwhelming consensus in the literature, as opposed to say, climate science. It's not surprising or suspicious in the least to see a contrarian result in this field.
- jasonjmcghee 4y ago
  Based on this comment https://news.ycombinator.com/item?id=34882990 https://news.ycombinator.com/item?id=34882990 - you seem to be spot on.
sys32768 4y ago
Don't a lot of drug addicts only eat once a day? And what about obese people eating three big meals a day? I feel great when I stop eating by 2 PM. Sleep better, have more vivid dreams, and more energy the next day. I'm reminded of an old doctor approaching retirement who told me longevity was largely luck and genetics.
pard68 4y ago
Likely this is because people who are dieting are overweight. This is looking at damaged people and then drawing a conclusion. Pretty good chance these people would have died similar deaths regardless of diet. Better study would compare them to a control group to determine if risk went down or if life expectancy went up.
- gitfan86 4y ago
  This is the elephant in the room with MUCH of the healthcare system. They report drug X or treatment Y resulted in a 40% improvement of outcome for patient. But what they don't say is people who didn't take the drug but avoided obesity and excess Alcohol, Drugs, Tobacco had a 70% better outcome.
  - bee_rider 4y ago
    Is it really an elephant in the room? Every time I’ve had a (luckily mild!) issue they’ve suggested lifestyle changes.
noughtme 4y ago
This is not a study about "intermittent fasting", it is about people who skip meals. I don't know why they skip meals, they don't know why they skip meals, but I would not assume these are all super health conscious people engaging in deliberate intermittent fasting.
- halfnormalform 4y ago
  Correct! The word "fasting" doesn't appear anywhere in the abstract. And the study also found that shorter meal intervals (i.e., the opposite of fasting) was associated with the same thing. Nothing to do with intermittent fasting.
jron 4y ago
This seems at odds with the numerous studies on longevity and caloric intake being strongly correlated.
ericmcer 4y ago
Your bodies requirements will constantly be changing based on your age and lifestyle. Fine tuning your diet is a personal experiment that never ends so any absolute is dumb.
ChrisMarshallNY 4y ago
I was wondering when we’d see this. There are so many variables in these things, that it’s damn near impossible to do truly neutral studies; especially if there’s any money to be made. https://m.youtube.com/watch?v=ahgjEjJkZks https://m.youtube.com/watch?v=ahgjEjJkZks
DueDilligence 4y ago
" .. no funding to disclose" tells me all I need to know about this feeble attempt as mis/disinformation that the food cartel is orchestrating. yawn .. next.
JohnClark1337 4y ago
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rossdavidh 4y ago
The title is "Meal Skipping and Shorter Meal Intervals...". That's not much like "intermittent fasting", which brings to mind things like not eating for a 24 hour period rather than skipping breakfast. The actual title of the paper would be a much more appropriate title for this post.
piqi 4y ago
literally nothing in the article mentions anything about fasting, intermittent or otherwise. This post should be flagged/removed.
- VernorVintage 4y ago
  Having a meal period <4.5 hours is a form of intermittent fasting called Daily Time-Restricted Feeding. You're fasting 19.5 hours each day. There are many intermittent fasting protocols including multi-day fasts which have been shown to prolong life in mice. But daily fasting is included in those protocols. A lot of health hype has focused on Daily Time-Restricted feedings. This kind of IF is typically characterized by a daily meal period of 8 hours or less, with only water or snacks under 50 calories allowed during the rest of the time. This is supposed to promote changes like reducing insulin resistance, but there are questions about the hype vs truth of this.
  - piqi 4y ago
    Like I said.... the linked article literally says nothing about "fasting." Feel free to quote the part that mentions it. It only discusses "meal skipping." No mention of snacking. > ...snacks under 50 calories allowed during the rest of the time. This is not fasting. Even just 20 calories is generally expected to stop the fast. 50 calories would definitely stop the fast.
    - VernorVintage 4y ago
      The article mentions feeding periods of <4.5 hours, which is a well known intermittent fasting protocol, which I have already defined. You have willfully ignored that, suggesting you might not respect my time or the truth. I caution you that you are using a nonstandard definition of fasting that does not include all the currently recognized forms of intermittent fasting. Nor have you presented a definition of intermittent fasting - it's likely your definition is too narrow to cover the current practices. I refer you once more to the wikiepdia article on IF (which leads . Again, the relevant term is "Daily Restricted Feeding". That information is here: https://en.wikipedia.org/wiki/Intermittent_fasting https://en.wikipedia.org/wiki/Intermittent_fasting It's entirely fair to regard the current research as having to do with Daily Restricted Feeding, which is a form of IF. And yes, the article does not mention snacking. I was simply claiming that some IF protocls even allow light snacks, to help persuade you that IF protocols are more diverse that you think. The goal of these protocols is to reduce things like insulin resistance, which happens when the body is in a physiologically fasted state. Some nutritionists claim a snack under 50 cals won't compromise the outcomes, supposedly because the 50 cals is too small to physiologically break the fast. This is informally called the "50 calorie rule", and it's relevant because the IF community and nutritionists sometimes endorse it. The point was to communicate that there is a variety of IF protocols beyond what you recognize as fasting. I will say that it's frustrating for me that you dispute well known concepts and trends in the nutrition community - at least acknowledge what I am saying, and give counter arguments if you disagree. If you can't, I will conclude your motivation here has to do with something other than seeking the truth about our state of understanding of IF. If that's the case, lets end the convo.
user052919 4y ago
The data was based on behavior between 1999-2014, which means it was behavior that almost certainly was not health motivated since intermittent fasting wasn't popular then. So I think you have to ask: why were these people skipping meals? I think there are a lot of possible explanations and they are all potential confounds. Like, one obvious reason people skip meals is that they don't have time. If you don't have time to eat, you're probably working long hours and really stressed out. Stress could easily contribute to CVD or otherwise take years off your life. Another obvious reason to skip meals: you don't have money to buy food. Poverty is well known to lead to worse health outcomes. Or one more: people skip meals because they have no appetite. What's a big cohort that routinely skips meals because they have no appetite? The elderly. Maybe they ruled these kinds of things out in the full paper (I've only read the abstract) but so far I'm unimpressed.
- CrazyStat 4y ago
  I pulled up the full paper. As you speculated, people who skip meals are quite different from people who don't, in ways that might be relevant to overall health outcomes: > As shown in Table 1, compared with participants with three meals per day, participants eating fewer than three meals per day were more likely to be younger, men, non-Hispanic Black, with less education and lower family income, current smokers, heavy alcohol drinkers, higher physical activity levels, lower total energy intake and lower diet quality, food insecure, and higher frequency of snacks. They control for these factors in the statistical analysis, to different extents in three different models: > Model 1 adjusted for age, gender, and race and ethnicity. Model 2 additionally adjusted for education, income, smoking status, alcohol intake, physical activity levels, total energy intake, HEI-2010 score, household adult food insecurity status, and snacks frequency. Model 3 further adjusted for baseline diabetes, hypertension, hypercholesterolemia, CVD, cancer, and BMI status, because these variables may be mediators between meal frequency, intervals and timing, and mortality. This is an issue. Controlling for the variables in the model helps somewhat, but it's inevitable that the populations are also different in other relevant ways that are not captured in the covariates (e.g. stress levels). They're also reporting dozens of results (18 in Table 2, another 18 in Table 3, 12 in Table 4) but doing no correction for multiple testing. Given that many of the confidence intervals only barely exclude 1, this is an issue. Finally, and most damning--the effects almost entirely disappear if they exclude people who had cancer or cardiovascular disease at the beginning of the study. This is hidden in the supplementary material of the paper, not discussed at all within the main body of the paper. Of the effects cited in the abstract the only one that survives excluding people who had cancer or cardiovascular disease at baseline is that people who skip breakfast appear to have higher risk of cardiovascular disease-related mortality. Given that the study is labelled "prospective" and one of the outcomes studied is death from cardiovascular disease, IMO it is dishonest to not note that the claimed effects disappear if you exclude people who already had cardiovascular disease when the study started.
Jamesbeam 4y ago
It's incredible to see how this site turned from valuable feedback in the comments to well...this. Half of the comments making assumptions that you can not make on the data provided, the other half seems to be IF Crusaders trying to justify their own "healthy" eating behavior as if their life depends on it. Here is a very simple thing to do when you don't understand a paper or how to interpret it. Send the Authors a mail and ask politely if they could help you understand their work better. There are multiple E-Mail Addresses provided from the Authors. Seriously "I feel great when I stop eating by 2 PM" is a fun comment, but feeling great and being healthy are not exactly correlated. I climbed Everest once and my body started dying at about 26000 feet, it felt amazing, still I was literally dying. Maybe I should just take a break from reading HN comments, it's not like it used to be.
- BaseballPhysics 4y ago
  > It's incredible to see how this site turned from valuable feedback in the comments to well...this. ... > Here is a very simple thing to do when you don't understand a paper or how to interpret it. Send the Authors a mail and ask politely if they could help you understand their work better. There are multiple E-Mail Addresses provided from the Authors. So, just so I'm clear: You're complaining that people didn't email the study authors and interrogate their work before commenting on the article here?
  - Jamesbeam 4y ago
    Thank you for asking. Everyone should feel free to express themselves and I always encourage people to contribute. I'd just appreciate if people spent more time thinking about if they actually have something to say that has any sort of value for me as a reader on the topic in return for the time I'm giving them to read their submission / comments, as a basic form of respect. In my opinion the steady decline of quality in comments and submissions, especially on scientific submissions posted here, is because a growing amount of people are not doing the minimal amount of research it takes to form an educated opinion about a topic. But getting the science wrong has very real consequences. For example, when a community doesn’t vaccinate children because they’re afraid of “toxins” and think that prayer (or diet, exercise, and “clean living”) is enough to prevent infection, outbreaks happen. To form a truly educated opinion on a scientific subject, you need to become familiar with current research in that field. And to do that, you have to read the primary research literature. Reading and understanding research papers is a skill which every single doctor and scientist has had to learn during graduate school. Everyone can learn it, but like any skill it takes patience and practice. Based on what I read in the comments for this submission, a lot of people do not want or can not spend that time on building an educated opinion on the topic and figuring out if the underlying paper has scientific authority. That's why I encouraged them to ask the Authors directly, if something is unclear or they are making assumptions that are simply not supported by the paper. I'd still appreciate if more people learned how to read and interpret scientific work but in a world where most people want instant rewards and have a rather short attention span, a short, polite E-Mail to the Authors is a shortcut to gain valuable insight on the scientific work and your own assumptions about it, so that you don't sound like a complete idiot to people who have actual knowledge about the topic when you say things like "Most people in this study were probably obese and would have died anyway" or "Probably junkies skipping meals". I could take time to explain this paper in an even lengthier comment, but I'm just Jamesbeam on HN. You have no idea if I'm a nobel prize winner or maybe having an agenda to persuade you into a certain direction, but the authors of this paper are actually scientists published in a reputable journal and they were so kind to even give you the ability to contact them by publishing their E-Mails. And yes, I think it's a good idea to challenge your assumptions by asking people with actual knowledge about the topic so you don't look like a complete fool on the Internet.
deleted 4y ago
[deleted]
ouid 4y ago
it seems this got flagged for all sorts of reasons, but one significant observation is that they threw away data for people who eat more than 5000 kcal/day as "implausible". Those people are likely to be among the most unhealthy, and also the least likely to skip meals, moreover if skipping a meal caused you to go from 5500 to 4500, this would create a pretty significant effect in the data.
goldforever 4y ago
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icare_1er 4y ago
Skipping a meal is not really what the trendy "intermittent fasting" really is... Intermittent fasting is fasting for 24h or even a few days ONCE IN A WHILE, that's quite far away from what's described here.

38 points by crhulls 4y ago

“Among participant with three meals per day, a meal interval of ≤4.5 hours in two adjacent meals was associated with higher all-cause mortality.” So people who ate three meals a day ALSO fared poorly? Am I reading that right?

pc86 4y ago
Eating three meals with a shorter meal interval has higher all-cause mortality than eating three meals with a longer meal interval. It's not saying anything about 3 meals vs. any other number of meals.
troydavis 4y ago
Only those who had less than 4.5 hours between 2 of their 3 meals. The lowest hazard rate/lowest all-cause mortality was among those who ate 3 meals a day and had 4.5+ hours between them.
VernorVintage 4y ago
None of us are reading it right yet. We're not interpreting the "Hazard Ratios" - whatever those are. Until someone comes along and explains it (or uses chatGPT/bing to explain it), there's no point to form opinions about these results. In addition, we need to know what percentage of the people were doing fasting, in order to determine if the HRs are statistically significant. That claim a 95% confidence ratio, but is that true? If we're not able to do this kind of simple checkup on the data, we will just confuse us even more when we find another paper that adds even more naunce and complexity to the issue. That's how people become anti-science. Because we don't understand /this/ work, this work causes us cognitive dissonance. And because we don't understand this work, our dissonance is even worse next time. I hope a kind statistician comes along and help our thread about by explaining the numbers and what they really mean in terms of death risk and life expectancy.

VernorVintage 4y ago

Can someone interpret the Hazard Ratios for me? What is a HR of 1.3 or 1.8 actually saying?

abecedarius 4y ago
Good question: it turns out I didn't know there's a technical difference between "hazard ratio" and "relative risk". https://en.wikipedia.org/wiki/Hazard_ratio https://en.wikipedia.org/wiki/Hazard_ratio But the basic idea is that in the samples under the two different conditions, the ratio of the observed frequencies is 1.3 or 1.8. E.g. it'd be 1.8 if in the fasting sample they saw 3.6% bad outcome, while in the nonfasting sample they saw 2.0% bad outcome.
- VernorVintage 4y ago
  Okay, wow so HR 1.8 literally does mean that fasters are nearly twice as likely to die over a given period as non-faster. But the death rate for fasters and nonfasters can still be pretty low, for example 2% a year vs 1% a year. Since the risk is low already, an individual might be indifferent to a 1% or 2% death rate - from an individual perspective the two are even statistically indistinguishable (they can't exactly die more than once!) Okay, I'm a little less freaked out by the seeming /doubling/ of death rate, however, it's still 2x increase in death rate. Still chilling! Now I suppose that if we assume the death rate is constant for everyone at all times - or use a more realistic actuarial curve - then we can even transform the HR factor into an average effect on lifespan for fasters vs nonfaster. Then we could say "ah, nonfasters will die on average 4 years sooner than nonfasters". I think that would help contextualize the numbers even better than relative death rates (which are hard for individuals to reason about). Are you familiar with how we might convert death HR into an expected lifespan delta for the average person? Would that analysis actually hold any meaningful truth?
  - abecedarius 4y ago
    > Are you familiar with how we might convert death HR into an expected lifespan delta for the average person? You'd have to integrate over lifespan using an actuarial table, I assume. This figure of 1.8 wasn't for all-cause mortality, but rather for heart-disease deaths among breakfast-skippers. I wouldn't worry (much) for a bunch of related reasons: - The more complexity you need to specify a statistic, the more evidence you need to overcome a presumption it's an artifact. (Some of this caveat shows up in how they report it ("multivariable-adjusted", "95% confidence interval"), but these frequentist-statistics methods don't really account for all the real-world reasons for doubt.) - This study was observational, not interventional. It's one study. Observational studies, particularly in epidemiology, particularly for diet, are often misleading. - What'd be the mechanism making skipping breakfast have this big an effect? There could well be a good answer to that, but it doesn't spring to mind for me. In other words, what was your prior on this hypothesis, before this paper? - I haven't read the paper beyond the abstract linked to, but https://news.ycombinator.com/item?id=34883541 https://news.ycombinator.com/item?id=34883541 lists some potential problems. - The process that brings a particular medical paper to your attention, unfortunately, is not much like one that optimizes for the most significant updates to the probability distribution you should have over hypotheses. Unless you have a much better news feed than most of us, anyway. I think of a result like this as a little bit of evidence to keep in mind as you learn more. It's not making me do anything different right now. That might seem harsh about a study involving "185,398 person-years of follow-up period" -- that must've taken a fuck-ton of work -- but it seems to be the world we're in.

jankyxenon 4y ago

The study period is from 1999 to 2014. IF wasn't a mainstream practice then - meaning that the bulk of people who try to eat healthy may have been targeting more meals in that period than recent years. Just a possible hypothesis.

p1esk 4y ago
I thought IF was more popular in the 90s than it is now.

mataug 4y ago

Associated !== Attributed https://en.wikipedia.org/wiki/Academy_of_Nutrition_and_Dietetics#Criticism_of_partnerships_with_food_companies https://en.wikipedia.org/wiki/Academy_of_Nutrition_and_Diete...

unloco 4y ago
Of course. I was wondering how eating less could cause death. That "academy" is sponsored by Wendy's and Coca-cola. The organization also publishes nutrition facts sheets for the general public, which food companies pay $20,000 to take part in writing the documents.[77] A list of these publications for the general public include: What's a Mom to Do: Healthy Eating Tips for Families sponsored by Wendy's.[78] Lamb: The Essence of Nutrient Rich Flavor sponsored by the Tri-Lamb Group.[79] Cocoa and Chocolate: Sweet News! sponsored by the Hershey Center for Health and Nutrition.[80] Eggs: A Good Choice for Moms-to-Be sponsored by the American Egg Board.[81] Adult Beverage Consumption: Making Responsible Drinking Choices sponsored by the Distilled Spirits Council.[82] This industry funding also gives food companies the ability to offer official educational seminars to teach dietitians how to advise their clients in a way that advances the interests of the food company. For instance, in a Coca-Cola sponsored seminar for dietitians, the speaker promoted free sugars consumption for children as a healthy choice.[83]"

icare_1er 4y ago

It's a bit like red wine, every week there's a new study proving the opposite of what the previous study said.

tqi 4y ago

They claiming a statistically significant hazard ratio within 1-6 years of a single survey response, that covers only the previous 24 hours? No other factors considered? This doesn't pass the smell test.

deleted 4y ago
[deleted]

irrational 4y ago

Maybe because those who are trying to diet are already obese?

throwaway1777 4y ago
A lot of people doing intermittent fasting are not obese. In fact a large portion of the people I know who do it are more athlete/biohacker types (I fall into this bucket myself)
madeofpalk 4y ago
I don't think intermittent fasting is 'weight loss dieting' In my limited personal experience, it's not obese people i see doing intermittent fasting - it's more like the keto crowd.
- Kelteseth 4y ago
  My experience tells me the exact opposite. I lost more than 20kg thanks to IF. I would not have done it, if it would not mean I will lose weight.
  - exfatloss 4y ago
    Keto-crowd and weight-loss crowd have a massive overlap. If you get into keto for fat loss these days, you will almost certainly encounter IF ideas and will likely try some form yourself. I have.
nequo 4y ago
Rather unfortunately, the paper is behind a paywall but the results use this phrase: the multivariable-adjusted HRs for participants That suggests to me that they controlled for BMI or other proxies for obesity.

deleted 4y ago

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rand0mx1 4y ago

Earlier, on HN I read that it improves lifespan and now it is associated with early death.

bayesian_horse 4y ago
Not the same thing... Also there can't be scientific evidence that anything improves lifespan.
- kaczordon 4y ago
  Of course there can be evidence.
- rileymat2 4y ago
  Can you speak more to "Also there can't be scientific evidence that anything improves lifespan." I am missing the subtlety, but I would think statistically with twin studies and controlled experiments you could?
  - bayesian_horse 4y ago
    There is always the difference between causation and association...
- sokoloff 4y ago
  I think there’s ample evidence that seatbelts and airbags save lives, thereby improving lifespan as compared to the control (same number of car trips). Similarly, avoiding or ceasing of habitual smoking of cigarettes has ample evidence for lifespan improvement.
  - bayesian_horse 4y ago
    There is a fine distinction between scientific definitions of causality and association, incident rates and survival time, and other concepts.... Colloquially all of that is a lot easier to state.

GalenErso 4y ago

Am I wrong to have suspicions about the possibility that food conglomerates may have funded this study? I am not a conspiracy theorist, but with the number of dietary science that turned out to be wrong over time, I must be skeptical about every new study.

LegitShady 4y ago
if you have some kind of evidence to believe that, you wouldn't be wrong. But without that evidence, yes, you'd be wrong to have suspicions just based on disagreeing with the result.
Calavar 4y ago
> with the number of dietary science that turned out to be wrong over time, I must be skeptical about every new study. This I agree with. There is so much noise and so many confounding factors affecting the underlying data that you are bound to frequently get conflicting results. Compound this with the fact that studies with the most surprising (read: contrarian) results tend to get the most press, and you get an infinite see-saw in the literature. > Am I wrong to have suspicions about the possibility that food conglomerates may have funded this study? This I don't agree with. I think your model of more fasting equals less spending on food is overly simplicitic. The sort of health conscious people who are interested in IF tend to be wealthy and willing to spend on premium health related products. I'd wager that you can make a lot more money selling a few premium, organic, protein bars that you pitch as premium feel-full-for-12-hour-guaranteed products than you can by selling the same old breakfast cereals. Besides, Occam's razor. Intermittent fasting is not a subject where there is or ever has been an overwhelming consensus in the literature, as opposed to say, climate science. It's not surprising or suspicious in the least to see a contrarian result in this field.
jasonjmcghee 4y ago
Based on this comment https://news.ycombinator.com/item?id=34882990 https://news.ycombinator.com/item?id=34882990 - you seem to be spot on.

sys32768 4y ago

Don't a lot of drug addicts only eat once a day? And what about obese people eating three big meals a day? I feel great when I stop eating by 2 PM. Sleep better, have more vivid dreams, and more energy the next day. I'm reminded of an old doctor approaching retirement who told me longevity was largely luck and genetics.

pard68 4y ago

Likely this is because people who are dieting are overweight. This is looking at damaged people and then drawing a conclusion. Pretty good chance these people would have died similar deaths regardless of diet. Better study would compare them to a control group to determine if risk went down or if life expectancy went up.

gitfan86 4y ago
This is the elephant in the room with MUCH of the healthcare system. They report drug X or treatment Y resulted in a 40% improvement of outcome for patient. But what they don't say is people who didn't take the drug but avoided obesity and excess Alcohol, Drugs, Tobacco had a 70% better outcome.
- bee_rider 4y ago
  Is it really an elephant in the room? Every time I’ve had a (luckily mild!) issue they’ve suggested lifestyle changes.

noughtme 4y ago

This is not a study about "intermittent fasting", it is about people who skip meals. I don't know why they skip meals, they don't know why they skip meals, but I would not assume these are all super health conscious people engaging in deliberate intermittent fasting.

halfnormalform 4y ago
Correct! The word "fasting" doesn't appear anywhere in the abstract. And the study also found that shorter meal intervals (i.e., the opposite of fasting) was associated with the same thing. Nothing to do with intermittent fasting.

jron 4y ago

This seems at odds with the numerous studies on longevity and caloric intake being strongly correlated.

ericmcer 4y ago

Your bodies requirements will constantly be changing based on your age and lifestyle. Fine tuning your diet is a personal experiment that never ends so any absolute is dumb.

ChrisMarshallNY 4y ago

I was wondering when we’d see this. There are so many variables in these things, that it’s damn near impossible to do truly neutral studies; especially if there’s any money to be made. https://m.youtube.com/watch?v=ahgjEjJkZks https://m.youtube.com/watch?v=ahgjEjJkZks

DueDilligence 4y ago

" .. no funding to disclose" tells me all I need to know about this feeble attempt as mis/disinformation that the food cartel is orchestrating. yawn .. next.

JohnClark1337 4y ago

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rossdavidh 4y ago

The title is "Meal Skipping and Shorter Meal Intervals...". That's not much like "intermittent fasting", which brings to mind things like not eating for a 24 hour period rather than skipping breakfast. The actual title of the paper would be a much more appropriate title for this post.

piqi 4y ago

literally nothing in the article mentions anything about fasting, intermittent or otherwise. This post should be flagged/removed.

VernorVintage 4y ago
Having a meal period <4.5 hours is a form of intermittent fasting called Daily Time-Restricted Feeding. You're fasting 19.5 hours each day. There are many intermittent fasting protocols including multi-day fasts which have been shown to prolong life in mice. But daily fasting is included in those protocols. A lot of health hype has focused on Daily Time-Restricted feedings. This kind of IF is typically characterized by a daily meal period of 8 hours or less, with only water or snacks under 50 calories allowed during the rest of the time. This is supposed to promote changes like reducing insulin resistance, but there are questions about the hype vs truth of this.
- piqi 4y ago
  Like I said.... the linked article literally says nothing about "fasting." Feel free to quote the part that mentions it. It only discusses "meal skipping." No mention of snacking. > ...snacks under 50 calories allowed during the rest of the time. This is not fasting. Even just 20 calories is generally expected to stop the fast. 50 calories would definitely stop the fast.
  - VernorVintage 4y ago
    The article mentions feeding periods of <4.5 hours, which is a well known intermittent fasting protocol, which I have already defined. You have willfully ignored that, suggesting you might not respect my time or the truth. I caution you that you are using a nonstandard definition of fasting that does not include all the currently recognized forms of intermittent fasting. Nor have you presented a definition of intermittent fasting - it's likely your definition is too narrow to cover the current practices. I refer you once more to the wikiepdia article on IF (which leads . Again, the relevant term is "Daily Restricted Feeding". That information is here: https://en.wikipedia.org/wiki/Intermittent_fasting https://en.wikipedia.org/wiki/Intermittent_fasting It's entirely fair to regard the current research as having to do with Daily Restricted Feeding, which is a form of IF. And yes, the article does not mention snacking. I was simply claiming that some IF protocls even allow light snacks, to help persuade you that IF protocols are more diverse that you think. The goal of these protocols is to reduce things like insulin resistance, which happens when the body is in a physiologically fasted state. Some nutritionists claim a snack under 50 cals won't compromise the outcomes, supposedly because the 50 cals is too small to physiologically break the fast. This is informally called the "50 calorie rule", and it's relevant because the IF community and nutritionists sometimes endorse it. The point was to communicate that there is a variety of IF protocols beyond what you recognize as fasting. I will say that it's frustrating for me that you dispute well known concepts and trends in the nutrition community - at least acknowledge what I am saying, and give counter arguments if you disagree. If you can't, I will conclude your motivation here has to do with something other than seeking the truth about our state of understanding of IF. If that's the case, lets end the convo.

user052919 4y ago

The data was based on behavior between 1999-2014, which means it was behavior that almost certainly was not health motivated since intermittent fasting wasn't popular then. So I think you have to ask: why were these people skipping meals? I think there are a lot of possible explanations and they are all potential confounds. Like, one obvious reason people skip meals is that they don't have time. If you don't have time to eat, you're probably working long hours and really stressed out. Stress could easily contribute to CVD or otherwise take years off your life. Another obvious reason to skip meals: you don't have money to buy food. Poverty is well known to lead to worse health outcomes. Or one more: people skip meals because they have no appetite. What's a big cohort that routinely skips meals because they have no appetite? The elderly. Maybe they ruled these kinds of things out in the full paper (I've only read the abstract) but so far I'm unimpressed.

CrazyStat 4y ago
I pulled up the full paper. As you speculated, people who skip meals are quite different from people who don't, in ways that might be relevant to overall health outcomes: > As shown in Table 1, compared with participants with three meals per day, participants eating fewer than three meals per day were more likely to be younger, men, non-Hispanic Black, with less education and lower family income, current smokers, heavy alcohol drinkers, higher physical activity levels, lower total energy intake and lower diet quality, food insecure, and higher frequency of snacks. They control for these factors in the statistical analysis, to different extents in three different models: > Model 1 adjusted for age, gender, and race and ethnicity. Model 2 additionally adjusted for education, income, smoking status, alcohol intake, physical activity levels, total energy intake, HEI-2010 score, household adult food insecurity status, and snacks frequency. Model 3 further adjusted for baseline diabetes, hypertension, hypercholesterolemia, CVD, cancer, and BMI status, because these variables may be mediators between meal frequency, intervals and timing, and mortality. This is an issue. Controlling for the variables in the model helps somewhat, but it's inevitable that the populations are also different in other relevant ways that are not captured in the covariates (e.g. stress levels). They're also reporting dozens of results (18 in Table 2, another 18 in Table 3, 12 in Table 4) but doing no correction for multiple testing. Given that many of the confidence intervals only barely exclude 1, this is an issue. Finally, and most damning--the effects almost entirely disappear if they exclude people who had cancer or cardiovascular disease at the beginning of the study. This is hidden in the supplementary material of the paper, not discussed at all within the main body of the paper. Of the effects cited in the abstract the only one that survives excluding people who had cancer or cardiovascular disease at baseline is that people who skip breakfast appear to have higher risk of cardiovascular disease-related mortality. Given that the study is labelled "prospective" and one of the outcomes studied is death from cardiovascular disease, IMO it is dishonest to not note that the claimed effects disappear if you exclude people who already had cardiovascular disease when the study started.

Jamesbeam 4y ago

It's incredible to see how this site turned from valuable feedback in the comments to well...this. Half of the comments making assumptions that you can not make on the data provided, the other half seems to be IF Crusaders trying to justify their own "healthy" eating behavior as if their life depends on it. Here is a very simple thing to do when you don't understand a paper or how to interpret it. Send the Authors a mail and ask politely if they could help you understand their work better. There are multiple E-Mail Addresses provided from the Authors. Seriously "I feel great when I stop eating by 2 PM" is a fun comment, but feeling great and being healthy are not exactly correlated. I climbed Everest once and my body started dying at about 26000 feet, it felt amazing, still I was literally dying. Maybe I should just take a break from reading HN comments, it's not like it used to be.

BaseballPhysics 4y ago
> It's incredible to see how this site turned from valuable feedback in the comments to well...this. ... > Here is a very simple thing to do when you don't understand a paper or how to interpret it. Send the Authors a mail and ask politely if they could help you understand their work better. There are multiple E-Mail Addresses provided from the Authors. So, just so I'm clear: You're complaining that people didn't email the study authors and interrogate their work before commenting on the article here?
- Jamesbeam 4y ago
  Thank you for asking. Everyone should feel free to express themselves and I always encourage people to contribute. I'd just appreciate if people spent more time thinking about if they actually have something to say that has any sort of value for me as a reader on the topic in return for the time I'm giving them to read their submission / comments, as a basic form of respect. In my opinion the steady decline of quality in comments and submissions, especially on scientific submissions posted here, is because a growing amount of people are not doing the minimal amount of research it takes to form an educated opinion about a topic. But getting the science wrong has very real consequences. For example, when a community doesn’t vaccinate children because they’re afraid of “toxins” and think that prayer (or diet, exercise, and “clean living”) is enough to prevent infection, outbreaks happen. To form a truly educated opinion on a scientific subject, you need to become familiar with current research in that field. And to do that, you have to read the primary research literature. Reading and understanding research papers is a skill which every single doctor and scientist has had to learn during graduate school. Everyone can learn it, but like any skill it takes patience and practice. Based on what I read in the comments for this submission, a lot of people do not want or can not spend that time on building an educated opinion on the topic and figuring out if the underlying paper has scientific authority. That's why I encouraged them to ask the Authors directly, if something is unclear or they are making assumptions that are simply not supported by the paper. I'd still appreciate if more people learned how to read and interpret scientific work but in a world where most people want instant rewards and have a rather short attention span, a short, polite E-Mail to the Authors is a shortcut to gain valuable insight on the scientific work and your own assumptions about it, so that you don't sound like a complete idiot to people who have actual knowledge about the topic when you say things like "Most people in this study were probably obese and would have died anyway" or "Probably junkies skipping meals". I could take time to explain this paper in an even lengthier comment, but I'm just Jamesbeam on HN. You have no idea if I'm a nobel prize winner or maybe having an agenda to persuade you into a certain direction, but the authors of this paper are actually scientists published in a reputable journal and they were so kind to even give you the ability to contact them by publishing their E-Mails. And yes, I think it's a good idea to challenge your assumptions by asking people with actual knowledge about the topic so you don't look like a complete fool on the Internet.

deleted 4y ago

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ouid 4y ago

it seems this got flagged for all sorts of reasons, but one significant observation is that they threw away data for people who eat more than 5000 kcal/day as "implausible". Those people are likely to be among the most unhealthy, and also the least likely to skip meals, moreover if skipping a meal caused you to go from 5500 to 4500, this would create a pretty significant effect in the data.

goldforever 4y ago

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icare_1er 4y ago

Skipping a meal is not really what the trendy "intermittent fasting" really is... Intermittent fasting is fasting for 24h or even a few days ONCE IN A WHILE, that's quite far away from what's described here.