If you look at the replies you'll see the huge variety of responses people have to this, which is absolutely fascinating. I think this might actually be different for different people.

I suspect it has to do not with being different people but with gut biome (so it can be different for the same person at different points in time, maybe even something we can change by changing our diet or surroundings).

It’s definitely different for different people. It will vary by age, health status, body composition, and fitness level as well.

I’m kind of perplexed at all of these anecdotes from people who tried fasting and assume their experience to be definitive for everyone.

Sure there might be different experiences, but that's what I'm critizising from the article, since it says it IS the same experience for everyone (hunger increases the longer the fast). I do agree I should probably have added an extra "for some/many" or two on my comment though.

Coz 90% of them missed the point in article that said they just "fasted" by not eating during day (Ramadan), and not some multiple day endeavour.

If you hook a hose up to someone’s mouth and nose and measure the ratio of O2 absorbed vs Co2 they expel, the so-called respiratory quotient (RQ), you have a measure of the types of metabolic processing they’re doing, anaerobic vs aerobic.

If someone is in a state of metabolic dysfunction, commonly due to unfit mitochondria, they’ll be unable to utilize energy from fat as well as a young, fit person. Their body is adapted to having access to carbs at all times. Some people call the opposite being “fat adapted”. During a fast, after they’ve burned through all their glycogen, fit mitochondria can still dependably access stores of energy from fat, of which we normally have plenty.

I would bet the people who never stop being hungry during a long fast are experiencing the effects of metabolic dysfunction due to a phenotype acquired from living in the high carbohydrate, frequent access to food environment that is modern living in a first world country, especially if America. I would bet money on measuring a different RQ for the two groups, both normally and during a fast.

I’ve gone on multiple 3-5 day fasts and disagree (or at least haven’t gotten to this point).

My hunger seems to stabilize at very hungry after about two days.

Same here. My hunger plateaued after two days, but didn't go away, just became a bit more bearable. 12 days was the longest fast I've done.

12 days with no food? Like just water and electrolytes etc.?

This is some spartan discipline.

Definitely doable and very common in many old cultures, have a look at the film "The science of fasting" (original German), might be eye opening: https://youtu.be/WgLJ_dfKy1E

> Video unavailable. This video contains content from LDS, who has blocked it in your country on copyright grounds

I hope LDS burns in hell, whoever they are.

Latter Day Saints??? The Mormons? (I get the copyright block message here in the USA)

I looked it up, and it's "content management company" Little Dot Studios, who seem to make money by claiming things on youtube to steal ad money and extort people.

Ugh. I hope the Mormons hit them with a trademark violation!

Same here. Guess they don’t like Ecuador.

Apparently the only whitelisted regions are DE and FR, so they don't like the majority of the people.

Why would you do this to yourself?

Last week I fasted for 5 days. Today I ate sugar again. I cannot speak for OP but my primary reasons were curiosity and becoming more aware of my body and energy levels. The last days I was super active, productive and in a crazy good mood. Today I feel like a slump. I probably will do it again and 5 days was much easier than expected. You probably need some experience to do it for 12 days, but I am very confident that it is manageable after the second or third time. It‘s like sport. People say „why would you do it“, but when you experience it by yourself you know intrinsically that it isn’t actually that bad.

Is it discipline? Or a medical condition? For example, I wouldn’t say someone with anorexia has impressive discipline. I can’t think of any reason rooted in reality why someone would fast for almost 2 weeks straight.

Same. 12 days. Was training like a machine I felt almost high. Very clear mentally. Lots of extra time. Wasn't particularly hungry.

I'm confused. You say "same", so you agree with arunix and jraby3? For them their level of hunger increased the longer they fasted. But then you wrote "wasn't particularly hungry", so you agree with franciscop?

Impressive if you did training while fasting btw!

I should have been more clear. For me at least, the peak hunger point was approximately 48hrs. It subsided substantially from there. I am fit and train often. But I've had a life long unhealthy relationship with sugar, which I managed to solve some months after I started fasting.

This reminds me of how some people argue they actually drive better when drunk.

Many studies have proven that:

1. Driving ability is impaired by alcohol consumption (or lack of sleep, incidentally)

2. People are very bad at estimating how severely impaired they are (wrt being drunk or kust tired)

Are there any similar studies around ability to mentally focus / perform physical activities while fasting?

Perhaps it depends on the intellectual load, and only doable if watching TV.

Haven't gone 3-5 days but done more than 1 day, hunger paradoxically goes from high to low/none in 24 hours. I can feel weaker but not hungry the way I feel at first.

After adjusting to rare meals I 100% feel better after 8 hours of not eating than when I eat often.

Do you spend physical effort during that time? Eg. exercise, move heavy stuff, intensely walk. (I don't)

Also what do you eat/drink before you fast.

Same. I’m over 24 hours into a fast right now. Zero hunger. I guess it’s different for person to person, kind of like just about everything seems to be.

At day three I was fine until I told myself I was going to get some food. Then I felt like I got hit by a truck in my stomach and nearly threw up I was shaking and so hungry. So I ended up breaking a three day fast at a Taco Bell instead of the grass fed steak I had waiting at home. Best Chalupa I’ve ever eaten in my life.

The body is a mystery! I guess biology is influenced by thought as much as the other way round...

You mean no food for two days? Agree you grow very hungry. But 1 meal a day, after a week or two it becomes a habit and you don't feel hunger, even though you are losing weight.

However make one exception, and hunger comes back immediately. Hard to get on those diets (hunger only goes away after a week) and stay on those diets (one exception, a loving mum who thinks it's not healthy, christmas, etc, and the diet is dead).

Maybe I am lucky, but for me it works like this:

If I skip food after (early) dinner and don't think about it more I can easily skip breakfast the next day and then I can easily skip lunch, dinner and supper the following day.

If I start to think about or expect food however I think I can easily get in trouble.

Disclaimer: I have only done this for 4 or so days.

What is mentioned in article (ramadan fasting) is essentially half day of fasting, not multiple day endeavour.

The longer north you come however, the longer the fast can become I understand as many (most?) Muslims looks at the local sunrise and sunset.

Agreed, I am an experienced faster. My longest fast was 5 days (no food mon-friday)

I've never felt "not hungry" during a fast. I think "I don't even feel hungry" is something people just say to cope. More like a mindset than an actual feeling.

Yep. Actually I feel myself turning into a wild animal. I can smell food from distances and food becomes my only thought.

But the SMELL of food!

I think my normal sense of smell is not great, but when hungry... It's just glorious.

It does depend on different people, but yeah peak hunger is around 2-5 days in (again depending on multiple things) so doing multiple 3-5 day fasts just seems torture to me when you could've done a longer one and not be so hungry in the process. I have done three 10+ days fasts (trying not to get stuffed just before) and usually at 2-3 days is the peak. Days 4-5 are also hard, and you might get a punctual "hunger pang" much later on depending on what's going on (e.g. walk by a pizzeria), but overall nothing at all compared to day 2-3.

This is based on the experiences that I've seen (as my comment before) derived from reading 10s-100s of people's experiences about fasting on Reddit groups over the years. Not scientific, but also not taken from thin air.

+1. And I’ve noticed about myself that the amplitude or my “peak” hunger drops significantly as I sustain more days of intermittent fasting. So the hunger becomes more tolerable, so to speak.

Totally same, if habitually snacking I can feel from "hungry" to lightheaded and shaky after a few hours of unplanned break, but when adjusted to 1-2 bigger healthier (less carbs) meals per day after a while my body is fine with 15 hour breaks and even more. At extreme I can feel physically weaker but not hungry. So "longer fast = more hunger" is definitely false for me and I guess depends on judges habitual schedule, physical activity and diet.

Correcting science with even worse science seems to be fashionable these days. Science at work.

All these sibling comments suggest it is 100% you that has the bias. Is it really not conceivable to you that this varies by person?

Modern humans have modern inventions like zero calorie foods. I’ve talked to many who have fasted where their body probably disagreed with that statement.

Zero calorie food is the very definition of an oxymoron. Emphasis on moron.

This is on same level of single use clothes

I don’t know if you are disagreeing with me but see: zero calorie sodas and sugars.

Zero calorie sodas are food?

I'm sure you can find much research about how the body reacts to it as such.

Ah, now I see your point. Still should not be called food, though. Unless I've been misusing the word my entire life

Something that may tickle your fancy is considering words as food. Food affects our body in more ways than simply giving us energy. Can words affect the mind in similar fashion?

food provides nourishment. surely there must be other, more specific terms for these zero calorie "food" things

That hasn’t been my experience. Recently I didn’t eat for a week (for medical reasons) and I felt awful the whole time.

best option is to just assume every psychology/social sciences article is bullshit, pretty much all of the most famous studies have failed to replicate. And many of those studies were used to justify trillions of dollars in federal spending over the past few decades

I think the best thing is to do more research to understand more rather than rejecting the scientific method entirely. It has and will continue to get better and better over time, with occasional regressions that may seem meaningful in the short term but are tiny blips when you zoom out. The history of science is one false theory being replaced by another that’s (usually) marginally closer to the truth.

So someone does a single dubious research, and we follow with 3 more dubious researches to justify the first research. For each of these 3 dubious researches we have to do 3 more to ensure their credibility. And the number of researches grows exponentially while the research quality doesn't improve at all.

peer review only really took off in the last few decades and it has been a disaster. Nothing about my post says anything about the scientific method, it's about sham fields that lack rigor and use cartels of influence to push each others pet theories to support their own ideologies.

Well this is somewhat ironic, but “citation needed” on that first statement.

simplest is a visualization of the term usage - https://scalar.usc.edu/works/the-art-of-academic-peer-review...

but looking at the criticism and history sections of the wikipedia page will cover it in more detail. It basically promotes gatekeeping and group think, as seen with the Alzheimer's research issue which wasted billions of dollars and slowed progress by decades via effectively an academic cartel. Funding becoming tied to publication which relies on peer review made things worse

https://en.wikipedia.org/wiki/Scholarly_peer_review

Indeed, the book The Quick Fix goes over exactly this point. For example, did you know that the Superman pose had no scientific evidence whatsoever? The researcher simply pushed for it because it made her feel good. The grit study by Angela Duckworth is similarly faulty, the cadet training camp she went to had a pass rate of over 90% so the ones who didn't pass weren't in a statistically significant group to show whether their grittiness actually meant anything to them failing or passing.

Here's some incontrovertible evidence of the effectiveness of the Superman position.

https://youtu.be/99K4gpJZWdw

I heard this is so effective, they had to ban it to keep the sport safe and fair.

If everyone can do it, isnt it fair?

It's like steroids in baseball. Anybody could do it so in that sense it may be fair, but it's unfair to all the players who aren't utterly reckless and short sighted.

So... I do think the superman position is effective, but I don't think a single video without any auditing is considered "incontrovertible evidence"

I think you missed the joke of the video.

Examples of 'failed-to-replicate-but-used-to-justify'?

Read the book The Quick Fix, which has many examples.

> And many of those studies were used to justify trillions of dollars in federal spending over the past few decades

Can you clarify where you beleive trillions were spent as a result of bogus social research?

Probably tough for psych research, but trivially easy for biomedical research, which has one or two orders of magnitude more money involved.

HN loves to critique psych research without understanding that once you're above chemistry in the complexity hierarchy, these problems are everywhere.

Yeah, as somebody who has experimented with fasting, I think it's a huge mistake to think that Ramadan fasters would respond like hungry non-fasters.

Fasting is a common religious practice because it is both a challenge and a discipline. To get good at fasting, you have to work to unlearn habits of instant gratification and learn to consciously lean against the urgings of the body. A fasting practice develops real skills.

It's perfectly plausible to me that Ramadan-observing judges would better at judging while hungry while non-fasters would get worse. So this article's author is doing exactly what he criticizes: assuming his naive model is the only explanation.

There is intermittent fasting research that has shown that fasting after a few days can end up decreasing sleep time and increase all-day energy. My own fasting experience shows this increase in energy and reduction in sleep as getting better and showing more energy in arguments. Some say this would be making me angrier but it isn't. It is making me more forceful at the argument.

Or, you’re getting cranky because you’re hungry.

> It's perfectly plausible to me that Ramadan-observing judges would better at judging while hungry while non-fasters would get worse.

I don't know for judges, but I live in a dominantly religious society and I haven't noticed the virtues promised by observing strict religious fasting. In fact, people have been jailed by (probably fasting) judges for eating out of sight [1].

[1] https://www-lepoint-fr.translate.goog/monde/algerie-2-ans-de...

If the laws says you should fast, it wouldn't be a virtue for a judge to not punish someone for breaking the law, unless the law gives the judges this liberty.

Now I am not saying I agree with this law, I am Christian and according to how I and those I live with practice it, fasting is strictly individual, something I personally would even try to hide according to Jesus words in Matthew 6. 16, 17 and particularly 18:

> «that thou appear not unto men to fast, but unto thy Father which is in secret: and thy Father, which seeth in secret, shall reward thee openly.» ‭‭Matthew‬ ‭6‬:‭18‬ ‭KJV‬‬ https://bible.com/bible/1/mat.6.18.KJV

That quote is quite interesting. I went to see if it's any different in other versions is bible, but it's always pretty much the same.

Maybe expressing that you're fasting could be seen as bad. As if you're trying to boast about it, how you're better then others.

Which made me that, if people that eat a vegan diet (or similar) kept it to themselves and not force it onto others, then perhaps there wouldn't exist the culture of "I ate a steak in front of vegans" or "I don't mind if you're vegan, but please let me eat in peace".

The first part Matthew 6, 1 - 21 has a lot more about doing what we do only with the expectation that God will see it, either it is alms, prayers or fast.

Each of these might have value on their own, but God will only reward us if we do it for him instead of doing it to seek the glory of men.

Don't Ramadan fasters only fast for a few hours a day (e.g. during daylight?) Do they ever reach the point where they've skipped enough meals to no longer be hungry? TBQH skipping meals during the day and eating one big meal after dark doesn't seem terribly unlike the lifestyle of many nerdy bachelors. I'm sure I've done that many times myself without even thinking about it.

Per this, Ramadan fasting is 13-15 hours per day: https://www.brandeis.edu/spiritual-life/resources/guide-to-o...

Since the non-fasting hours include a night of sleep, that schedule sounds pretty rigorous to me. Americans typically have an eating window of 12-15 hours, eating 5 times per day: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8705992/

The Ramadan fast also includes not drinking any liquids, which many people find to be the most difficult part of the fast, especially considering the types of climate a majority of the Muslim population lives in. It also requires people to be awake during the day to do all their mandatory prayers, so the sleep during the day strategy wouldn’t really work. You basically have to get up for the pre-dawn meal, unless you want to wake up dehydrated from sleeping, and wait 10 or so hours to have your first glass of water. The fact that the dates of Ramadan move every year also means that you’re expected to experience the fasting during all of seasonally different lengths of day your location has (if you live in a place that has no sunset I believe the religiously permissible solution is to fast according to the schedule of Mecca).

I dunno about getting better, but yeah the dropoff would be less pronounced.

My theory for why it might go the other way: to get good at fasting, I had to get better at noticing and leaning against feelings that might throw off my judgement. Hunger was the feeling at issue, but I think it's at least partly transferable to other feelings.

Ramadan fasts aren't really much as far as fasts go. They last only during daylight hours and you can stuff yourself silly in the mean time.

I just attended an Iftar a while back. The amount of gluttonous eating, wastage of food and lack of hygiene in cleaning up the area after the Iftar was astounding.

It's of course no surprise then that most Muslim cities see the maximum amount of food wastage, and most Muslims the maximum weight gains during the month of Ramadan. Not to mention how overworking the ladies of the house in preparing the Iftar , while the men laze around, seems to be a common theme transcending across cultures. And I say these as a Muslim.

In my opinion, water fasts make more sense than silly daylight fasting. My stomach seems to agree with that too - Ramadan always seems to exacerbate my auto-immune condition.

Gluttony and moderation depends on the local culture. I've personally witnessed iftars on both sides of the spectrum.

* * *

Agreed - this person may not have experienced ketosis and how it feels.

I've done a waterfast before and for me this point was somewhere around the beginning of the third day. I could've kept going really, but I noticed my body had started to break down muscle (day 8.)

Doing something on purpose is completely different than not having a choice at all, psychologically.

I have been working remotely for 15 years, that’s how I like it. But the two years of pandemic with forceful social distancing were really hard.