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Fasting 3 days each quarter (tomkwhite.substack.com)
36 points by smitec on Oct 22, 2020 | hide | past | favorite | 79 comments



As someone with extensive experience fasting, some thoughts.

> My goal is to get into Ketosis before the water fast begins.

This is great, it's much easier to start a fast when you're in ketosis.

> I keep my water intake high during the week, attempting to drink between 4-7 litres of water per day.

This is way WAY too much water, especially if you're drinking anything on top of it. Shoot for 2.5 to 3.5 liters a day maximum. If you do this for any prolonged period of time, or multiple weeks in a row, you're going to have issues.

> This is why the fasting once per week doesn't work for me. I think it is just repetitive torture every week with minimal fat burning and quite a disruption to normal socializing.

Yeah, that's because you're doing it wrong. I'm on week 4 of 5/2 (fasting/eating) and it's sustainable. So long as I don't eat pure junk on my 2 days, it's not even that bad for the first 24 hours. I have one friend who maintained this schedule for a year and a half, and another who's been at 96+ hour fasts for over a year now.

> Cooking whilst mid-fast is torture

I didn't find that to be the case. I cooked for my girlfriend plenty on my 60 day fast. Wasn't that big of a deal. Didn't start until after the 2nd week though, so that may have something to do with it. I guess I can see it on shorter fasts if you're not adapted though.

> "Threw some salt in my water, feel a fair bit better after that might do this once a day."

Yeah... this individual and I need to have a talk about that. This guy says he's 75kg, drinking 4 to 7kg of water a day, for 3 to 5 days, without _ANY_ salt to speak of. The average human is 55 to 60% water by weight. Do you have any idea how hard that is on your kidneys? Or what it does to your salinity levels?


> This is way WAY too much water, especially if you're drinking anything on top of it. Shoot for 2.5 to 3.5 liters a day maximum. If you do this for any prolonged period of time, or multiple weeks in a row, you're going to have issues.

Source? Or what kind of issues? I average 5~8 l on a normal day and have been for years. The few times I've had my values checked they were mostly fine, apart from the lab being hassled by the huge sample they got for my 24h urine. Naturally I have a bit higher salt intake than most.


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

Beware of hyponatremia - you're aware of your salt intake, sure, but it's not just salts in blood that are important!

Hyponatremia can also remain asymptomatic for a long time: https://en.wikipedia.org/wiki/Hyponatremia#Acute_versus_chro...

It sounds as though your high intake of water _works for you_ but anecdata does not mean it wouldn't become a health issue for somebody else. Especially if they only do this when fasting and 5-8L isn't their regular intake.

https://www.medicalnewstoday.com/articles/318619#how-much-is...

In theory you could drink slightly under 24 litres a day (assuming you never slept haha) - but your kidneys would have to be working in top form to excrete that 0.8 to 1 litres per hour.

The danger appears to be chugging large quantities of water every couple of hours, which I imagine fasting newbies are more likely to consider to get that "full" feeling


Of course everyone's body is different so you may be fine but 5~8 l for an average person migt be too much. For me personally it might seem crazy looking back to my high school years where I reguralry drank less than 1 litre on days with no physical activities, but I know I was fine back then and was not thirsty.

General advice I have seen is to drink when thirsty and more on hot days, or drink so much that your urine is slightly yellow but not all transparent. Drinking too much water flushes out more minerals from your body. A woman have died after drinking too much water for a contest [0], but that is of course an extremen example. It can happend though.

[0] https://www.theglobeandmail.com/news/world/drank-too-much-wa...


> Source?

A mountain of personal experience fasting for extended periods of time. Back of the envelope, over 200 days in the last 3-ish years.

If your salt intake is higher than normal, and you don’t fast for extended periods of time, it’s not applicable.

In general everything about fasting becomes difficult when your electrolytes get outta whack. It’s been my experience that almost everyone who’s otherwise healthy, with ample access to food, and no experience fasting will confuse their body screaming ‘I need salt’ with ‘I’m thirsty’ —- In the developed world we almost never experience the former.

Too much water is just as bad as not enough.


It's funny how electrolytes are still ignored or overlooked by the fasting and keto communities. This meme of doing a "water fast" is bullshit, IMO, and people need to stop talking about it because chugging water doesn't help when fasting unless you're actually dehydrated. Drinking water just causes the body to urinate out more electrolytes, which is exactly what you don't want on a fast. Most people on HN could easily not drink any water for a couple of fasting days, and they'll realize just how overrated water is as a necessity for daily health. Your fat cells, your muscle cells, your glycogen stores, all have metabolic water in them. There's no reason to take in excess water unless you are running low on metabolic water, in which case your body will actually scream for water.


> It's funny how electrolytes are still ignored or overlooked by the fasting and keto communities.

I see you've never visited /r/keto on reddit, then... It is very much pounded by the regulars, and in every guide they recommend. IIRC, /r/fasting is also aware (though not as pedantic about reminding everyone).

Which communities are you referring to?


Fasting I'm not sure, but maybe we've been frequenting different keto communities?

Daily supplementing magnesium/potassium/nacl seems to be part of the standard routine from what I've seen and it commonly comes up on the /r/keto and /r/ketogains.


Agree wholeheartedly.

We’re all bound by the inexorable grip of diffusion, and there’s only so much our kidneys can do to stem the exodus.

Quite miraculous little hunks of tissue though.


So I usually hit 1L as I wake up. I am always dehyrdated when I wake up. I usually crush out another 2-3 litres across the rest of the day. With tea I suspect that it pushed me upwards of another litre. If I work out I'll usually have another waterbottle worth. This is basically what I would do normally.


The word “ketosis” gets thrown around a lot. It’s a physiological state that’s objectively quite hard to enter. I would ask, are you quantifying if you are “in ketosis” or not at any point during your fast, and if so how? Or is this just a gut feeling?


> It’s a physiological state that’s objectively quite hard to enter.

No, it isn't. The human body developed to bounce in and out of ketosis all the time. It's only hard to enter if you are always in a fed state and rarely in a fasted state. When you're fasting, it's not particularly hard to get back into ketosis in the same day, although it can take 24 to 48 hours for someone who isn't getting even light exercise. That's still way, way faster than the weeks it can take to get into ketosis on keto. (unless maybe you want to eat mostly protein and little fat, which is miserable)

I speak from extensive experience. A few weeks ago, after a 72 hour fast, I chowed on a pile of salmon sushi, measured my ketones throughout the day with ketone test strips, and was back in dark purple by the end of the night. Though normally it takes until the next morning for ketones to start showing up in my urine again, I believe it happened much faster because I was walking a lot that day. That was impossible to do back when I was just eating strict keto macros.

Anyone who doesn't believe me should try themselves by doing a few 72 hour fasts and refeeding on high protein, moderate carbs. They'd be surprised that it doesn't take an unreasonable amount of time to get back into ketosis. It's a perspective changer because it shows that occasionally eating carbs socially isn't the end of the world, because you'll be back in fat burning mode within a day or so.


So you can objectively track when your “bouncing” in and out of ketosis, like say for instance the way your heart beat changes ?

urine test strips only measure acetoacetate. Urinary ketones often correlate poorly with serum levels because of variability in excretion of ketones by the kidney, influence of hydration status, and renal function. (Wikipedia - I’m being a bit lazy).

I’m not arguing against fasting, or low carb diets. I’m making the point that ketosis isn’t as easy to “bounce” into as people think (though it doesn’t mean there are not benefits from fasting or low carb diets).


Your urine isn't going to show acetoacetate unless you're in ketosis. You're not supposed to use ketones to test accurate levels. It's to give you an idea of what's going on. There's no way your strips are going to show purple if your body isn't producing ketones for energy transport. The exact level doesn't even matter that much because what shows up in the urine is excess. Sure, acetoacetate is not the only ketone, but it doesn't just get created within the body for no reason. If you are fasted and you eat a bunch of ice cream, your ketone strip test will plummet to showing no signs of ketones at all. If you are fasted and you eat a fatty steak, at best you might see a slight decrease because of protein intake. This is consistent and easy to reproduce. I've repeated this test dozens of times. Carb and sugar heavy food plummets urine ketone levels and keto macros don't. Your body isn't going to produce an appreciable level of ketones when it's got simple carbs ready to go, which is because the body is going to prefer glucose every time it's given a choice.

And yes, you do bounce in and out of ketosis when you fast long enough, and it really doesn't take that long. Once you've expended your glycogen and you've digested all your food, your body doesn't have a choice but to dig in to fat stores. Depending on how much glycogen you have stored, what you've eaten, and how long it's been since you've eaten, getting into ketosis becomes ridiculously easy because the energy your body uses has to come from somewhere. You don't need to measure ketones to have confidence in this. It's well studied. If someone thinks that ketosis is hard to enter, I doubt they've gone more than a day without food. Once you get used to fasting for longer than 48 hours, it becomes obvious when your body is out of glycogen.


I suspect what the keto community calls "fat adapted" is basically that "easily bouncing in and out" state -- which some people reach easily, and some take weeks or months to achieve on keto. (but as far as I know, takes at most 3 days to achieve while fasting)


I am not sure if I have the correct understanding, so correct me if i am wrong.

Ketosis is not some magical mind state.

When all glucose and glycogen reserves are exhausted, body will start producing energy by burning fat reserves. To do so it needs to produce ketones. When low or glucose body will gradually start switching to ketosis to supplement energy needs and eventually fully switching to ketosis and only way of producing energy.

When glucose is available it will be used as primary 'fuel' source again.

That is a reason why after fasting its important to ease in the cards and sugars.


That's a reason, but likely not the only reason. There are likely reasons relating to regulation of other digestion processes that slow down to a halt while fasting.

Coming up from a fast and eating a lot of food quickly may cause refeeding syndrome - regardless of whether it is carbs or protein/fat.

Switching back to carbs from pure fat or pure protein is not dangerous in the same way, AFAIK (but I'm not a doctor).


> and if so how?

I use ketosis strips (Ketostix). You pee on them, and they tell you. Totally worth the 5$ they cost.

I'm happy in full ketosis, or no ketosis at all, but the "half-way" ketosis state is just pure torture.

The strips let me know how good I'm doing, so if things deviate a bit, e.g. because one day I ate ""too many carbs"", I notice quickly, and auto-correct.


Been my experience that these vary widely depending on hydration levels. Also I’ve heard/read, and I’m not sure how accurate this is, you can think of ketones in urine as ‘overflow’ and thus aren’t always an accurate portrayal of how much your body is producing.

On top of that, your body gets more efficient at using ketones as an energy source over time so your urine ‘overflow’ can spike at various points just because your body consumes less ketones for it’s energy needs. All of that is latent knowledge from random reading over the last 4 or so years, so grain of salt and all that.


How easy is the blood testing?


This ^


Literally testing my blood, with a medical device.


Can you recommend one from your experience? I'm in the market for one. (Preferably one that doesn't need prescription)


Abbot Precision Xtra is the most accurate, unfortunately the strips are expensive to the tune of 3 to 4 USD per strip if you get them new. NovaMax is also decent, though I’ve found it to be not quite as consistent or accurate.


Thanks!


Individual here for you to talk to. "On my 60 day fast"... Mate - you are in the big leagues compared to me. For us mere mortals smelling meat cooking while I'm hungry kills me . As for salt, I do have salt now. Found out the hard way. Your mileage may vary.


> As for salt, I do have salt now. Found out the hard way.

So did I, it’s a lesson I won’t forget.


Sorry, but curiosity forces me to ask.

How did you remain alive on a 60 day fast? I've never heard of that aside from maybe gurus in India or something.


While these aren't common, they aren't as uncommon as you think.

A famous long one is https://en.wikipedia.org/wiki/Angus_Barbieri%27s_fast ; But from memory reading studies about it ages ago (mostly examining religious fasters in India), an average non-overweight person can easily do 40 days water fasts without any irreversible damage. Somewhere between 40-50 days, the body would start to digest the nervous system for energy and that's irreversible (and leads to death within days if the fast continues). But if fat stores are available - as in the case of Angus Barbieri above - it can go for much, much longer.


You don't need to have 'magical' powers to do it.

https://en.wikipedia.org/wiki/Angus_Barbieri%27s_fast


I was much fatter than I am now. If you’re curious email me (in my profile) and I can share my spreadsheet with notes.


You did not eat anything for 60 days? 0 calories?

I heard people doing it for 14 days for fasting purposes and I am pretty sure that most people can do it for 30-40 days and not die, but 60 sounds pretty long


True zero cal, water/salt only, for the first 30, and too much water and not enough salt as I later found out.

From days 31 to 60 I allowed the occasional magnesium, potassium and multivitamin.

No coffee, no tea, just water.


Are you saying salt is needed or should be avoided?


salt is necessary to regulate water levels in cells. Without enough salt your cells will start dying- Hyponatremia.


If you are healthy with all your organs intact (e.g. - you did not have an appendectomy, any part of your digestive system shortened), you can easily do longer fasts - 10 or even 20 days.

Appetite generally goes away at day 2 or 3, so day 7 is usually easier than day 2. Highly recommended for physical and mental benefits, from my experience.

(This is not medical advice. I am not a doctor and don't play one on the internet. For all you know, I might be a dog).


> you can easily do longer fasts - 10 or even 20 days.

Not gonna argue against this but reading some comments here I feel like HN is full of health quackery sometimes.


Most people can water fast for a few weeks, unless you are very lean to start with. That doesn't mean it's easy... there are a LOT of social queues that can trigger a response... but the hunger really does go away after a couple days.


"Social cues" rather than "social queues."

I don't mean this as a tell off, just that it had me confused for a second. :)


It is not quackery. It has been proven over and over and over that fasting is good for your health. Even longer fasts (10, 20, 40 days or longer).

Check these out for starters

https://www.richroll.com/podcast/alan-goldhamer-541/

https://www.amazon.com/Rational-Fasting-Arnold-Ehret/dp/1884...

https://www.diabetes.co.uk/blog/2018/02/story-angus-barbieri....

Even religions agree on the benefits of fasting. Muslims, Hindus, Jains... all do fasting.

Fasting gets bad rep because people do it wrong, especially breaking the fast.


I would not consider Muslim or Jewish fasting a good example.

Both Jews (on "Yom Kippur", Day of Atonement), and Muslims (On Ramadan) do a "dry fast", that is - without any liquids either. That fast CANNOT be sustained for long, and becomes dangerous after just a couple of days regardless of your fat/energy reserves.

Jews do it for 25 hours once a year, and traditionally eat an extra lunch upfront ("Mafseket" - "The pause meal") and a regular-to-larger dinner afterwards. Muslims do it for a month, but only during daytime - and feast all night (some who can afford to, just sleep all day and stay up all night and don't actually fast). Neither of these traditions are healthy in any way.

I'm not as familiar with the Hindus and Jain fasting traditions - but I know some of them last months and all of them involve water drinking, so those are likely indeed healthy.


Do you have any reading on the relationship between fasting and having had an appendectomy? Never heard of this before


I do not, it's an inference I made based on my own experience. I'm not sure fasting after an an appendectomy is dangerous, but I suspect it might be - and that it's almost surely not as useful.

I am vegetarian. I had suffered from low B12 since early childhood, to the point of neurological symptoms in my early 20s (which were resolved by monthly B12 injections for a while, and then oral supplements). I slowly stopped taking them while still monitoring, and was stable at the very low end of what's considered acceptable.

And then, I did a 25 day fast (not even intentionally at first - I was sick with something, lost my appetite, and didn't eat for a few days; and then I felt great, but still had no appetite, so I didn't eat. It took 25 days for my appetite to come back).

I did get my blood tested just before the fast, including a B12 test, and it was low. My GP decided to do a full battery including B12 a month after I stopped fasting (usually only tested once a year or so) - and it was at the high end of normal (any higher, and it would have been suspicious). And it has been between the middle and high end of the range ever since.

At the time (over 20 years ago), this was considered impossible, or some unlikely miracle. However, since then the function of the appendix was discovered, which explains this perfectly:

The appendix is a backup store of good bacteria that the body maintains "just in case", because the digestive system is hostile (and we make it even more hostile by e.g. using antibiotics). It can go wrong, causing the appendix to rapture, potentially with bad consequences.

The conditions under which the body uses this backup to restart good bacteria cultures has not been well characterized yet, but IIRC it does include fasting and starvation.

Also, it is known that B12 is synthesized by bacteria in the gut (of humans or animals - the B12 you get from meat was synthesized by the same class of bacteria in e.g. cows - who similarly suffer low B12 because of extended antibiotics use, and who get B12 supplements these days as well).

So, my conclusion is that -- for the purpose of restarting your gut cultures -- fasting won't work if you don't have an appendix. I suspect, but do not know, that this might be an important part of why fasting works as well as it does, and might even be a requirement.

... which is why I wrote it the way I did.


> The conditions under which the body uses this backup to restart good bacteria cultures has not been well characterized yet, but IIRC it does include fasting and starvation.

That is very interesting, and would make sense given we evolved in feast/famine environment.


This is awful advice:

1. As the author suggests, a lot of that weight loss is just water. It'll come straight back again.

2. Getting into ketosis can take more than a day. Hell your body might even still be processing the carbs for quite a while as your food makes its way slowly around your digestive system.

3. 7 liters of water is tonnes. You risk flushing out your minerals. It's really not recommended. Adding some salt isn't enough.

4. Zero calories vs low calories when doing a low-carb diet doesn't really make a difference, your limitation is just around how much body fat your body can convert to useful energy when you need it.

5. When your body runs out of body fat it can easily source, it starts eating muscle. That's not just your arms and legs, that's things like your heart.

6. If you're not eating your body tries to convert whatever it can get into food. That would include the multi-vitamins he takes.

7. When you come out of ketosis, you should do it slowly. Transition from a high fat, low carb, small protein to increasingly more carbs and proteins. Grabbing a take-out or ribs and ice cream defeats the point.

8. Fasting only really works over short periods. When your body realizes something is wrong your survival mechanisms kick in, you go into starvation mode. Your metabolism drops and you start conserving energy rather than burning it.

To lose 1kg, all this guy has to do is make one small adjustment to his daily routine. One less sugar in his coffee, one less take-out a month, a little more cardio, etc.


I mostly agree with your points, but not entirely. Here are some comments:

> 4. Zero calories vs low calories when doing a low-carb diet doesn't really make a difference

That's not so clear cut. At the very least, anecdotal evidence indicates that zero calories reduces appetite much more than low calories does (to the point of elimination usually). This may have to do with smells or flavors of food, or may have to do with the activity level of some digestive processes. There is some evidence (from Cabanac's experiments, for example), that the calories are secondary, and smells+flavors are much more important than the amount of calories.

> 5. When your body runs out of body fat it can easily source, it starts eating muscle. That's not just your arms and legs, that's things like your heart.

Yes, but it starts with unused muscles first, and does that before or in parallel with fat. Luckily, your heart is in constant use, so it gets eaten last. This is the reason that you must exercise while fasted if you don't want to lose muscles.

> 7. When you come out of ketosis, you should do it slowly. Transition from a high fat, low carb, small protein to increasingly more carbs and proteins. Grabbing a take-out or ribs and ice cream defeats the point.

Total agreement here, and one should be aware of https://en.wikipedia.org/wiki/Refeeding_syndrome

> 8. Fasting only really works over short periods. When your body realizes something is wrong your survival mechanisms kick in, you go into starvation mode. Your metabolism drops and you start conserving energy rather than burning it.

Define "short". Seems to be 14-30 days before any significant drop in metabolism not attributable to "no need to digest", if you are active. In my experience, one DOES conserve more energy - e.g., a friend remarked that I lifted my legs less when running while fasted, and that my motions were otherwise "more energetically economical". But e.g. my body temperature was higher than usual.


1. Agree for the first 24 to 48, disagree thereafter.

2. True, depends heavily on diet. The liver and muscles can store a ton of glycogen. Also this is where a lot of the water weight comes from. Dunno about OP, but I’m in a pretty quick 12 to 18 hours back into ketosis pattern with fasting now.

3. Strongly agree, it’s too much.

4. Disagree completely, huge difference metabolically in calorie restriction vs calorie abstinence.

5. Somewhat agree, but the caveat I take issue with is ‘easily’, also most people who will be reading this post are likely quite far away from ‘running out of fat’.

6. Rounding error.

7. Agree.

8. Strongly disagree. I was burning the same 3500kcal or so per day on day 1 as I was on day 60 of my fast, experienced little to no metabolic slowdown.

> To lose 1kg, all this guy has to do is make one small adjustment to his daily routine. One less sugar in his coffee, one less take-out a month, a little more cardio, etc

For some people, It’s easier and more sustainable to just not eat sometimes.


> 1. Agree for the first 24 to 48, disagree thereafter.

It'll still come back.

> 4. Disagree completely, huge difference metabolically in

> calorie restriction vs calorie abstinence.

Yeah, with one you risk your metabolism slowing down. In terms of fat burning, there shouldn't be that much difference. There is only so much fat your body can convert into energy at any one time, if you go over this you're in trouble.

> 5. Somewhat agree, but the caveat I take issue with is

> ‘easily’, also most people who will be reading this post

> are likely quite far away from ‘running out of fat’.

You don't need to run out of fat, you just need to run out of accessible fat. You have an upper limit to how much you can instantly access, the process takes time. That's why people carb feed just before exercise to increase their workout performance, otherwise you'll literally run out of energy and crash.

> 6. Rounding error.

I'm not talking about an increase in weight, I'm talking about the vitamins not having the desired affect.

> 8. Strongly disagree. I was burning the same 3500kcal or

> so per day on day 1 as I was on day 60 of my fast,

> experienced little to no metabolic slowdown.

It of course depends per person, but metabolic slowdown is a real concern.

To me it sounds like this person switches from fasting to OMAD (intermittent fasting) + VLCD, which is still unsustainable over long periods but is much more sustainable than a water-based diet.


> 1. Agree for the first 24 to 48, disagree thereafter.

a neat-pick. That is BS. If you dont eat for 24 to 48. You will loose roughly 2500 x2 calories worth of weight.

And

On top of that you will loose weight due to water being dumped from you muscles. After refeeding that amount of water will be reabsorbed 'gaining back the weight'.

So its not like you have to fast for +3 days to loose some weight.


Good thing I plan to take 2-3 days to get into Ketosis, and good thing I have about 5% extra body fat so my heart is safe. Point of fasting for me isn't weight loss - pretty happy with my rig as it is. Why should you transition out of ketosis slowly?


Your metabolism increases when in fasted state:

https://youtu.be/tIuj-oMN-Fk (see 21:50, on mobile, can’t copy exact time)


You might find this old reddi post interesting.

Really seems like a lot of the benefits of calorie restriction and fasting may come from the fact consuming food produces damaging by-products, note the way you cook the food strongly influences how much of these by products come in the food itself, but your body also produces the. AGE's = Glycation products.

https://old.reddit.com/r/longevity/comments/iowh0d/dietary_a...


I plan to do a 3-day fast twice a year from now on, already did the first one in June. The main problem for me is that these long fasts take a significant toll on your muscles. After the first one, I noticed that I had lost strength and endurance. Basically you'll have to spend a few weeks training only to get to the level you were at before the fast.


This is the main reason why I don't and won't fast. The author claims that food is not actually a daily need, whereas I know for a fact that I will injure myself cycling or climbing if I skip even a single large meal in a day. It's a noticeable difference.


I do maintain a workout schedule but not as intense as yourself. Sounds like you're running pretty close to the edge of all your limits if you can't skip even a single meal.


or alternatively, addicted to something in his regular intake; An opiate addict will also not function as well without their regular dose.

(This is the first account I hear from someone who will get injured from missing a meal. That said, if you have to be addicted to something while keeping in top shape, food sounds like a better deal than opiates).


I didn't mean to exaggerate that badly but climbing is a sport where your ups and downs are very noticeable. If I don't have a solid lunch and climb in the evening, chances are I will get injured trying to do limit moves. I try to ensure I stabilise my diet and not risk that aspect, just no point for me to skip any.


Agreed. If you do any intensive training for endurance sport, the math just does not add up. Even with a very efficient fat-burning metabolism (that I don’t have), there’s only so much fat on your body and muscle mass will be affected. Yes, I do do metabolism-focused sessions of long uniform low-intensity effort without prior eating to get my body used to burning fat. But it takes a lot of time for it to learn it


Were you exercising on these 3 days?

My experience (from longer fasts - never felt anything like that after 3 days) was that muscles that aren't in heavy use do indeed get metabolized for energy (which makes a lot of sense - maintaining muscles costs energy; if you're not using them and running on fat reserves, why keep them?)

However, if I exercise while fasting, I hardly lose any muscle at all.

One interesting thing is that unaerobic exercise, such as boxing or rope skipping becomes harder for me while fasted; but aerobic exercise, specifically, running - becomes easier and it feels like I can keep running forever (whereas unfasted I usually feel my ability degrading near the end of a 10km run)


Yes, when the body is in a caloric deficit in enters a catabolic state where it will consume existing tissue, i.e. fat and muscle, for energy. For me it was definitely noticeable after just 3 days of not eating. Exercising might reduce the loss of muscle mass to some extent, but most people will still lose some or a lot.


> Exercising might reduce the loss of muscle mass to some extent

That does indeed seem to be the case, at least for a 16:8 intermittent fasting regimen (an 8 hour eating window with 16 hours of fasting): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5064803/

"Our results suggest that an intermittent fasting program in which all calories are consumed in an 8-h window each day, in conjunction with resistance training, could improve some health-related biomarkers, decrease fat mass, and maintain muscle mass in resistance-trained males."


I think this has more to do with your body switching fuel sources than actual loss in strength or endurance.


No, there was an actual, measurable loss. I noticed, for instance, that I could do fewer push-ups. That was after I had resumed eating. During the fast I wasn't exercising at all.


While fasting can be very beneficial, be careful if you're going to do it for long periods. A few days is ok but I wouldn't recommend anyone fasting longer without supervision.

David Blaine almost dies after 44 days of fasting. Not because of the fasting but because of how they fed him afterwards. He also say he hasn't recovered and his body sometimes acts weird. There's a clip of him talking about this on Joe Rogan Podcast.


Important: https://en.wikipedia.org/wiki/Refeeding_syndrome

The problem with recommending "supervision" is that there isn't anyone certified to do that in particular; so that's not really helpful.

I recommend anyone who wants to try fating to spend a month on /r/keto and /r/fasting , read all their tutorials, read some posts and ask questions; and then make up your mind about what kind of supervision (if at all) you want.

It's not a cult; people report bad experiences on these communities as well, and are not ridiculed or excommunicated for it.


Well, doctors are very well versed in these matters. Maybe not in long fasting but they can tell if something is going wrong with you.

I felt I had the obligation to post it.

Anyway, I wouldn't do anything extreme by the sake of doing it.


I did a 35 days water fast in July, I lost 12 kilos (from ~70 to 58) and then gained them back as I hit the gym again.

You can see the chart here.

https://i.ibb.co/rydPXDR/Screen-Shot-2020-10-22-at-3-07-52-P...

The top chart is weight and the one below is fat mass in kilos.

It was one of the most enlightening experiences of my life.


Just curious, you returned to your previous BMI or gained muscle mass instead?


Once I finished the 35 days fast, I started going to the gym. Body fat dropped from ~24% to ~10% on the fast and now up to ~18% after 2 month bulk, so I added more muscle mass, but I had a lot of work as well so I was not able to hit the gym as often as I'd like and I had extra calories.

The biggest surprise to me was I was way more focused and attentive but I couldn't sleep much (sometimes 4 hours max). And at some point I got "keto rash" but it faded away eventually.

I think if you do the fast and then break the fast with stricker caloric diet and more protein you can gain lean muscle mass, but I got worried when I reached 58 kilos as people started pointing out how skinny I got..so I started bulking up again..


Thanks for sharing.

> but I got worried when I reached 58 kilos as people started pointing out how skinny I got..so I started bulking up again..

Its important not to swing too hard in other direction too.


> I couldn't sleep much (sometimes 4 hours max) Did you find some way to mitigate this or did you just have to live with it during the fast?


I lived with it.

At the beginning I was really worried, but as I said I was very alert despite lack of sleep/food and I was able to work etc.

My personal take from this experiment, was that we don't need that much food/sleep to thrive, but again that was my personal experience, and I wish there was more research on that instead of the constant mainstream message (sleep 8 hours and eat 5 meals etc.)


On day 2, add about 100ml of clarified butter or as we call it Ghee. Ketosis kicks in much faster, helps you stay strong without any hunger pangs as Ghee will usually act as a lubricant and cleanser for your inner organs. It is also all Fat and there is tonne of literature on benefits of ghee in Indian Vedas.


lubricant and cleanser for your organs? sounds legit.


Nutrtional science is the most garbage natural science at this moment.

Simple proof: no one knows what the best diet is, hundreds of scientists and skin-in-the-game athlethes are bickering and trying different things out but no-one still knows anything.

No one knows that the best foods are for longevity and performance. Such a thing would need a full-generational study. You cannot just "I tried a diet for 1 month and X and Y happened".

1 month is nothing. At least 6 months are needed, 2 years in major changes can still be happening.

Also god forbid you trust the offical food pyramid, so many of these "stupid bro science" advices can have a lot more truth to them than the "offical advices" because they were tested via skin-in-the-game.


That closing remark of yours really hits the nail on the head, best sources are those who've lived it. Of course, the plural of anecdote is not evidence, but it's hard to argue with what works.


Works for a given individual. Your metabolic system is so non-linear and feedback-ridden, that people have not found a way to “know” anything. Why do you think the science is crap?


Alternatively just chug some WD40.


Don't know about the "lubricant and cleanser", but it has two relevant scientifically verifiable properties:

1. It's fat, which helps get fat soluble vitamins (if you take them while fasting) digested and metabolized.

2. Butter at least (likely ghee too, but I'm not sure) is full of butyrate, the metabolites of which are heavily involved in ketosis in humans (and is hypothesized to promote ketosis, though I don't know if that was conclusively demonstrated)




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