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Intermittent fasting associated with increased risk of early death

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Re: Intermittent fasting associated with increased risk of early death

#61

Post by Jamesbeam »

BaseballPhysics wrote: post #59
Jamesbeam wrote: post #58

Earlier quoted context omitted.

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 qualit…

Honestly, and I mean this with all due respect: You're being unreasonable. A study gets posted to Hacker News. You seem to expect every single person who wishes to discuss the study to first become an expert in the subject matter ("To form a truly educated opinion on a scientific subject, you need to become familiar with current research in that field.") and deeply engage with the material at the level of, if not an…

Thank you for your honest opinion. I respect that. And no worries, I don't feel offended. I assume good faith from your end.

Like I said in my original comment and you coming to the same conclusion, maybe after eight years of reading daily and interacting whenever I had something to say on HN it's time to dial down my overall interactions with HN and look for a different kind of community.

People change, and so do communities. Maybe it's time to move on.

Re: Intermittent fasting associated with increased risk of early death

#63

Post by VernorVintage »

piqi wrote: post #45
VernorVintage wrote: post #43

Earlier quoted context omitted.

Having a meal period 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 t…

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.

The article mentions feeding periods of 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

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.

Re: Intermittent fasting associated with increased risk of early death

#64

Post by VernorVintage »

abecedarius wrote: post #40
VernorVintage wrote: post #14

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

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 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.

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?

Re: Intermittent fasting associated with increased risk of early death

#66

Post by abecedarius »

VernorVintage wrote: post #64
abecedarius wrote: post #40

Earlier quoted context omitted.

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 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.

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 exactl…

> 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 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.

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