[SemanticStrengh]

This guy should be dead, his body should have digested himself. How can someone not eat anything by his own will for more than a few days ? (5-7 max) you should pass out. Also in the case that were true, let me be clear: No food intake for multiple days is extremely dangerous for your health, it will upregulate autophagy, apoptosis and will break your mitochondria bioenegetics which will explode your oxidative stress (and therefore DNA breaks) and will induce partial ischemia/hypoxia/hypoglycemia which leads to an accelerated ageing process. Autophagy is nice, in little dose, and is best emulated pharmacologically (e.g. via some polyphenols)

[lm28469]

That's not how it works at all. Not drinking water will damage/kill you real fast, not eating food on the other hand is pretty safe for most people. The longest fast was ~380 days [0]

If you have some fat (75% of westerners are heavily overweight or obese) you can easily fast on water only for weeks, of course you're not going to be able to exercise heavily every day or run a marathon. But if you're an overweight office worker with no other health issues you'll be just fine.

For anything over a week you probably should get medical assistance to keep an eye on vitamins and electrolytes, but you're not going to drop dead/unconscious/destroy your DNA

What's dangerous is starvation, aka fasting until your body starts giving up, but for the average westerner that's going to take a long time.

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

[beagle3]

You actually should exercise while fasting. When fasting, t he body gets rid of fat, and any muscles that are not essential. Which makes a lot of sense - maintaining muscle costs both protein and energy, even if they aren’t used much.

I did not try to run quickly while fasting, but I did keep doing my 5km 3 times per week, and the gym. Anaerobic was hard and quickly tiring, but aerobic exercise wasn’t really any harder.

A friend did point out that my movement was “more economical” in general - I hardly lifted my feet while running or walking, and a few other things. But I didn’t feel more tired or more strained, except for unaerobics.

[SemanticStrengh]

1) there are tons of substances the body can't make out of nothing/lipids. 2) there are tons of substances the body can't make efficiently with no food, which leads to metabolism/health deficits. and no it's not just vitamins and electrolytes LOL it's much more complex and diverse than that.

3) even if we assume in an ideal world, that the person who fast is able to supplement ALL the useful things and yet not take any external calories/glucose. This person would still reach a huge bioenergetic deficit/stress. Yes he will survive as you say, and might even be asymptomatic but nonetheless I would be very surprised if the biomarkers where doing Okay. Default bloodworks analysises are shit but if you command a proper analysis of your antioxidants ratio and of your bioenergetics biomarkers and apoptotic biomarkers you will see (unless I'm wrong which is very unlikely given my expertise) that the body is having a significantly accelerated aging/damage scheme. Which might not show symptoms before multiple decades later and even might not show symptoms at all in his life but statistically, there is a risk. Now he can mitigate some of those, by taking e.g. ALCAR + NAC daily for a year.

BTW the guy you linked died at 50 years old, which is not a performance.

[lm28469]

You went from "This guy should be dead" after 30 days of fasting to "this one guy died 25 years after a one year fast".

All I'm saying is that you were wrong. The human body can take much more than you explained in your first comment. You won't die nor fall unconscious and "5-7 days max" isn't anywhere close to the limit

[SemanticStrengh]

yes I was wrong on the potency of the damages, that does not refute my valid concern about transiently asymptomatic damages.

[travisporter]

What are bioenergetics biomarkers and apoptotic biomarkers? Google doesn’t give me a reliable source

[SemanticStrengh]

There are many. For apoptosis induced by mitochondria deficits you look at the level of cytochrome C. But there are others. For oxidative stress, a good indication is the ratio of reduced glutathione (how much of your antioxidants are being used)

for bioenergetics I don't remember the relevant ones although the manifestation is not only molecular, it can be observed (mitochondria respiration rate, uncoupling, etc) maybe this paper can show the relevant ones? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4715336/

[lm28469]

Are you comparing fasting to breathing aluminium particles ?

[SemanticStrengh]

well I was not, only that between those two stressors, the same major biomarkers are involved. There often is a surprising level of similarities between seemingly distinct things and here I would bet there are possible comparisons however that is not the point of my parent comment, just an answer to which biomarkers are involved. A more direct comparison would be with the acutes and long terms damages of hypoxia, because oxygen is a similar cofactor bottlenecking energy production, as is the absence of glucose/pyruvate from a fasting human which singlehandely rely of lipid/beta-oxidation. e.g. https://pubmed.ncbi.nlm.nih.gov/21542052/ But it's not because those are the same mechanism (a bottleneck on a critical cofactor for ATP) that the effects have the same potency because of course fasting is less dangerous in strength than hypoxia.

[rhinoceraptor]

I've done a few 7 day fasts, two 14 day fasts, and one 28 day fast. Every time it gets a lot easier. I'll be a bit hungry on days one and two, but by day three I only really think about food if I smell something good. As long as I keep up on water and electrolytes, I feel great.

[Terry_Roll]

18days here and would carried on but had to break it for other reasons.

Glutathione possibly needs to be included as this will get low and Choline or Carnitine to remove the brain fog that occurred.

Averaged 18kg weight loss over the 18days, never felt so good in my life, like being a teenage male ramped up on Testosterone again, amazingly easy to fall asleep, excellent quality of sleep, vivid dreams which are recalled in the morning, not nightmares or anything like that. Foods which I dont like because of historical reasons smelt appealing and I wanted to eat them, no cravings for anything.

The only water I could really wanted, was the Scottish Highlands water, just didnt like Evian, S. Pellegrino, and the supermarket brands, and I wonder if highly filtered water ie dead water with no contaminants so its almost pure H2O would have been what I wanted, but they dont sell that in supermarkets AFAIK.

Ramadan is one of the fasts where you dont consume fluids during the day, and not consuming fluids will ramp up parts of your immune system which is why its important to drink fluid in order to not get angry. This could be in part because histamine is used by immune cells to move through tissues, but a personality side effect of high amounts is increased aggression. Anyone who supplements with histidine a precursor for histamine may also notice increased aggression. ie explosive rage, so be careful.

[chronogram]

Most supermarkets do sell demiwater (distilled/deionised), which is great for chemistry or cleaning of electrical components, as well as having a standard base (with mineral packets) for brewing coffee or beer. I would definitely not drink it, especially not without heavy supplementation of minerals, else you lose more minerals from your water circulation than the 0 that you gain.

[Terry_Roll]

Sometimes its the chemicals in the water that cause the problem.

During my fast, my sense of smell became super good but the smell of chlorine in the tap water was disgusting, I couldnt drink the stuff.

[HanMei_333]

18 kg in 18 days is probably a typo. While fasting you never burn that much calories.

2-3 kg per week is a realistic number.

[TimSchumann]

I averaged 1.3 lbs/day for the entire length of my 60 day fast, and the first two weeks were much higher weight loss than usual. I can see 18kg in 18 days depending on what size you are. Of course 2-4kg will be water weight and another 2-4kg will just be stuff that lives in your gut, which is to say you'll gain it right back when you start eating again.

I just rolled into day four of a fast and the delta from two days ago is 3.72 kg.

Most of the weight you lose in the first 3 to 5 days of a fast isn't fat, its stuff in your gut and losing water as you draw down your glycogen stores.

[Terry_Roll]

So the water I was drinking I added a pinch of salt to it so I was drinking salty water. Obviously that will increase the Th17 cells but the number of immune cells drop off when you dont eat because generally the immune system attacks some of the food we eat, starch is one of the sugar's it wont attack.

[Terry_Roll]

Its not a typo, I did lose that much weight.

[SemanticStrengh]

This is a very complex topic and Glutathione or NAC has a half life of only ~5 hours. Had I to do it I would take ALCAR 2000MG but still you are playing with a lot of unknowns phamarcologically speaking. As i said a lab test of bioenergetics level, oxidative stress and apotosis are needed to bring confidence.

[Terry_Roll]

> you are playing with a lot of unknowns phamarcologically

Totally agree, but maintaining brain function is my priority the ALCAR may also help considering its similar to choline.

[adrianN]

It depends on how much fat you have. The body is relatively good at living on stored fat for a while. You need to supplement things that aren't stored, like vitamins and electrolytes and you'd better do it under medical supervision. If you fast long enough you also need some amino acids.

[SemanticStrengh]

You have zero idea of the propensity of hidden damages

[beagle3]

Surely there’s documentation you can point us to, since quite a few people have been fasting for a month at a time for ages?

But I’m only looking for documented examples, not extrapolated theory (which is what your first response seems to be), as — already in this thread - we have examples of 60 and 380 day cases with no observable I’ll effects (and I’ll add my own, multiple 15-25 days over the years, starting about 25 years ago — with doctor verified no I’ll effects a month later in most of them)

[adrianN]

I'm not saying that it's healthy. I'm just saying that many people have successfully fasted for surprisingly long intervals without dropping dead.

[DyslexicAtheist]

It sounds like you never tried?

I watched my dad do 30-60 days every few years growing up. He always said how clear it made him mentally and the benefits to his health also was visible (until today he mountain-bikes across South East Asia during winter and he is in his late 70ies).

Longest I did was 40 days. Started out with 10 days a few years earlier which broke my misconceptions about if I would be able to do it. Especially the 40 days has been a healing journey for me both physically and mentally. It also gave me massive confidence about my body and taught me more about my limits than what decades of running did. I wouldn't do this long again because I lack the reserves today. But 10-20 days every few years is no issue.

[TimSchumann]

I'm really surprised at the number of people in this comemnt thread who think going a week without food will kill you. I don't even think it will harm any healthy adult in any way, much less kill them.

[TimSchumann]

Not sure why I’d pass out from just not eating, I had plenty of body fat on me for the entirety of the fast. I wasn’t starving myself.

Estimating by weight loss my metabolism was still burning well over 2500kcal daily at the end of the fast.

[HanMei_333]

Agreed. Pretty much my numbers as well - around 300 gr weight loss a day.

An example:

A person with 14 % body fat and 74 kg body weight has around 10 kg fat. That is more than enough to go for about 30 days without any calorie intake.

[TimSchumann]

Yeah, my weight loss was around 1.3 lbs or 600 grams daily. I'm a large human though.

[amelius]

I guess he ate some bugs in his sleep.