[beagle3]

> Eating nothing for three weeks?! That's stupid and dangerous.

To quote other people on this thread - "citation needed". I've done this more than once, actually, and I know others who do too.

Yes, I have eaten essentially nothing for three weeks. No, I wasn't putting my life at risk of anything, though you may believe what you want -- did you notice that I'm not the only one who posted about long fasts? You just assumed everyone was eating, but we use "fast" literally, not as a codeword for "calorie restriction".

Although I had the references to support that it's healthy, I did do bloodwork a couple of times through, and at the end, it was -- in fact -- much, much improved. For example, my B12 levels went from -2 sigma to +2 sigma. (If this sounds impossible to you, read the wikipedia entry about B12 - the general "knowledge", even among doctors, about B12 is unbelievably incorrect).

My doctor, who is a reasonably open minded MD, looked at the results and said "just make sure you start eating when you are feeling hungry". That happened 21 days after I started. He wasn't worried after looking at my bloodwork.

If you're healthy at the beginning, irreversible damage starts around day 40 (but is very swift at that point). There are quite a few people in India who do 30 days every year for religious reasons, and suffer no ill effects -- and have been doing this for centuries.

[Jd]

Given what you've said here, I highly suspect you do long-term fasting within some sort of "yogic" context. I personally suspect that many of the potentially negative outcomes of dietary depravation are mitigated when in a positive environment (i.e. lots of nature / with good energies) complemented with certain types of yogic practices. There is also a long tradition of long "fasts" within Chinese qigong traditions, and the supposition is usually that a body attuned via various practices can feed off of the environmental energies (e.g. the sun, the mountain) without needing nutrients of other sorts. The technical aspect of some of these things is a bit beyond me, both because it is 'esoteric' and doesn't fit into any model of Western science that I know of (with the potential exception of Paracelsusians).

Along these lines, I'm curious what sort of environment you or the other people you know do their long fasts in (i.e. if there is a checklist of sorts).

[beagle3]

> Given what you've said here, I highly suspect you do long-term fasting within some sort of "yogic" context.

Actually, no. I'm hopelessly unreligious and unspiritual (or whatever the right adjective for "yogic" is).

> Along these lines, I'm curious what sort of environment you or the other people you know do their long fasts in (i.e. if there is a checklist of sorts).

I know some people who practice it in nature or a retreat of some sort, usually in some "yogic" or equivalent context (i.e. with others doing the same, and usually with a guide)

However, myself (and a couple of friends who followed after witnessing the effects on me) were doing it in the everyday environment, with no special support or anything.

In fact, that first 21-day fast happened accidentally - it was finals time at the university, which meant I spent all of my time studying and exercising (I discovered exercise makes studying much more effective). And then I was feeling really sick for two days (nauseated, congested, tired), and lost my appetite. And then I was well again, but my appetite didn't come back - so I didn't eat. (And those two days were the only days of that month that I didn't spend ~2 hours doing physical exercise)

After 4 days, I was starting to get curious - I was feeling better and better all the time, mildly euphoric even, and yet disgusted at the thought of food. Long story short, within a couple of days I found quite a few trustworthy references that were compatible with what I was going through, and that mentioned that even if I don't feel appetite coming back by day 30, I should eat.

A called my (conventionally trained, though unusually open minded) MD just to be sure, and he said "let's do some bloodwork to negate illnesses (a) (b) and (c) which cause loss of appetite and need treatment, but otherwise - just keep listening to your body". Which is also why I know that my B12 improved significantly through the fast. And indeed, I did feel hunger after 21 days. (And hunger is actually a different beast than appetite - a beast I think almost no one in the western world knows - it is a feeling of "i must eat now" that does not go away when you're doing something interesting, which is very different from regular appetite in ways I can't really put into words)

Later fasts felt good, but not as good -- possibly because my starting condition was better.

[Jd]

Fascinating. What were the "few trustworthy references" you found? I've never heard anything like your experience before, and the anecdotal evidence I've heard regarding fasting is largely gathered from spiritual traditions (i.e. Yoga, Christian, etc.).

[beagle3]

1. My grandmother was a doctor who had treated a lot of holocaust survivors, and collected their stories, which she later told my entire family. Several were about "miraculous improvement" in health conditions; some of it was, of course, survivorship bias (no pun intended ...) - those who were killed first where the less healthy and less able. But my grandmother had medical reasons to believe that a big part of it was nutrition (or rather, lack of it for long stretches at a time) -- especially because after the war, with the availability of a variety of foods, many illnesses came back. On that week, I verified with the family that I remembered her stories and conclusions correctly.

2. I found a book by Bernarr McFadden http://en.wikipedia.org/wiki/Bernarr_Macfadden (can't remember the name right now) that correctly described my experience (it's hard to find descriptions at all; and everyone around has the anthonyb opinion that I'm about to die because I haven't eaten in x days). That book had very old references (from the '30s) about fasting practices in some indian castes - which I was then able to altavista (that was before Google hit the scene) and confirm

3. I consulted my doctor, and a friend who had finished his medical studies and was doing his internship at the time. Both had the immediate anthonyb reaction, but a few minutes later conceded that any of the things they feared would trigger horrible pains, blackouts, etc - and that couldn't be right as I was feeling good.

YMMV. 1) and 3) may not be available to you. 2) was available to me from the university library, but I'm not sure where I can find it today. But it was available to me at the time.

[anthonyb]

Your b12 will be up because your body is cannibalising its tissues to stay alive. That's your liver, kidneys, etc. and it doesn't mean that you're healthier.

Given that you don't know that, and earlier on you didn't know what ketosis is, I'll take your dietary advice with a large grain of salt...

[beagle3]

Wow. I mean, you have all the answers!

I did know what ketosis is. But ketosis DOES NOT induce acetone breath in 99.9% of the population*time - which is what I understood you asserted. Look it up. Really, look it up.

And you better read about b12. You are radically misinformed. Not that I care - it's your health that will suffer. Really. Look it up.

[anthonyb]

No, you go look it up: http://en.wikipedia.org/wiki/Vitamin_B12#Foods.

What's the top source of B12 on that list? Now, given that you're not eating beef liver, which liver do you think is providing all that B12?

Stupid. Dangerous.

Edit: Thinking about it, I'd put fasting for 3 weeks in the same class as running a marathon: if you can do it, you're probably healthy. Actually doing it though, is not healthy at all.

[beagle3]

No, you read the article you quoted: Under "Foods", the section you linked:

... Ultimately, animals must obtain vitamin B12 directly or indirectly from bacteria, and these bacteria may inhabit a section of the gut which is distal to the section where B12 is absorbed.

Under "synthesis and industrial production":

.... Neither plants nor animals are independently capable of constructing vitamin B12.[30] Only bacteria and archaea[31] have the enzymes required for its synthesis.

And a little later:

.... The total world production of vitamin B12, by four companies (the French Sanofi-Aventis and three Chinese companies) is said to have been 35 tonnes in 2008.[40] Most of this production is used as an additive to animal feed.[41][citation needed]

It doesn't matter what the top source on the list is if you can have it synthesized in your own body. Which I now do way better than I could before my first fast. You know why cow liver has B12? Because cows are fed B12 these days so that beef liver would have enough B12 for human consumption! That's so ridiculous and inefficient it is sad.

You know why B12 synthesis is so horrible among both humans and livestock today? Because of how much we use antibiotics. And there's also another surprising finding: The human body (and most other mammals as well) have a cache of the organisms required to synthesize B12 and a host of other useful stuff. It's called "The appendix", you might have heard about it. The body will release these organisms from its cache under ketosis lasting more than a few days, to replenish and revive the useful colonies. Nature is very smart like that -- a few days of fasting are completely normal when your food source dries up. So the body uses that period to do maintenance. [I'm not going to spend time looking for the refs right now, partly because I no longer have access to full article texts, and mostly because I don't have the time; But this was hypothesized decades ago, and AFAIK conclusively proved something like 5 years ago, although it's not really well known so far even among professionals who should know better]

> Stupid. Dangerous.

Religious, is all I can say about your responses. You know things to be right, like it is dangerous to fast, or (I assume, although you might already be enlightened about these subjects) that dietary cholesterol is bad for you (it's almost independent of blood cholesterol, which is an important marker, though not a cause for disease), that you shouldn't eat more than a few eggs a week (nonsense; eat as many as you want - 20 a day is not unhealthy), that low-fat dietary intake is good for you (it's not), that butter is bad for you (it's excellent for you if it's from healthy grass-fed cows), that weight change is exclusively a result of caloric balance (only in the useless tautological sense), that you should minimize salt intake (too little is as bad as or worse than too much), or that cushioning is good for your feet and that's why sports shoes have them (they're bad for you except for very specific circumstances; they were championed by marketers, not researchers).

I try to challenge my beliefs and understand why I have them. I often (way too often, unfortunately) find that things everyone (including myself) takes for granted are actually better classified as "wrong leaps of faith" or even downright superstitions than science.

When someone contradicts me (and it's something I haven't researched and do not have a good basis for my beliefs), I try to start again from a blank slate, rather than find support for what I believe in (because you always can do that, regardless of how wrong you are).

> Edit: Thinking about it, I'd put fasting for 3 weeks in the same class as running a marathon: if you can do it, you're probably healthy. Actually doing it though, is not healthy at all.

I don't think this analogy is proper.

Evolution surely did prepare you to run short distances. Evolution did not prepare you to run a marathon - you have to practice to be able to do that, regardless of how healthy you are - and I agree it is probably not healthy (although I have no support for that - for all I know, done properly, it might be super healthy).

Evolution did prepare you to survive if your food source dries up (at least for a short while), or if you sprained your ankle and can't chase your prey or climb the tree to get food. In fact, it's apparently piggybacked some maintenance jobs on this period because (at least pre- agriculture) they were guaranteed to happen relatively often.

You may argue about how long that "short period" is - evidence collected mostly from religious fasting is that it is around 40 days when you are healthy.

> if you can do it, you're probably healthy.

I disagree in general, but there's an important point here that I must stress - it would probably have been unhealthy for me, had my appendix been removed (which is not uncommon), given the explanation above. However, the reason I started fasting was not religious or weight motivated - I simply had no appetite. So I didn't eat. The appetite came back 21 days later. I have since fasted several times in periods of 7-21 days, once every couple of years, sometimes prompted by loss of appetite, and sometimes by wanting to experience the health benefits.

I would not be surprised if appendix removal would have triggered appetite much earlier. And I would also not be surprised if evolution did not prepare humans for a removed appendix, and I would have suffered some irreversible damage as a result. I really don't know about that. (If you feel vindicated about this being "stupid and dangerous" - we have a difference of philosophy here, that I'm not going to argue about)

* edit: Forgot to mention - I've been vegetarian for the most recent 90% of my life, and vegan for a nontrivial part of that - during which I never had a good source of B12. If B12 could only be sourced from food intake, I'd be dead before the age of 12 (which is why I already knew 15 years ago that the prevailing B12 theories were bullshit, despite not having a better explanation at the time). But I was only dangerously low for a 6-month period in my twenties - other than that, I was just "low, but not dangerously so" until that fast.