[bresc]

I don't understand why it's potentially so dangerous to try it out on your own. Fasting is kinda natural. Assuming you go back to the roots and live in the forest. You are not going to eat every day... so why is it suddenly so dangerous? Some explanation on the risks would have been helpful.

[mmahemoff]

I understand health advice sometimes has obnoxiously overcautious disclaimers, but the warning seems valid in this case. It's referring to people who already have a serious condition - diabetes - reminding them not to suddenly make a major intervention in their eating routine.

[cloverich]

This was my thought. To add on, any dietary change that has major impacts on a diabetic's blood sugar levels, specifically if they are taking insulin, can be life threatening. Taking the wrong insulin dose with low blood sugar can and does kill people.

[cmdrfred]

Also and probably more to the front of the lawyers mind who reviewed this paper prior to publication. Cause of death may be difficult to determine and if you engaged in this fasting and then happened to die even if fasting was not the cause of your death it would be likely your family would have grounds to sue. Even if the publisher won the lawsuit he would be out legal fees, thus a notice like this is prudent on almost any actionable medical information.

[sjcsjc]

I agree. I've been water-only fasting five consecutive days every two weeks for over a year now (largely but not entirely as a result of Longo's work).

I assume that telling people they need medical guidance before doing so is a means of avoiding liability should someone do something stupid.

The only plausible risk I've seen mentioned, by Longo himself, is in women where the risk of gallstones might be increased. To quote him "Water-only fasting should only be done in a specialized clinic. Also, certain types of very low calorie diets, and particularly those with high protein content, can increase the incidence of gallstones in women at risk." [0]

The idea that water-only fasting should only be done "in a specialized clinic" seems daft to me, but in a litigious society I can understand why he says that.

Other researchers worth following in this area are Mark Mattson and Luigi Fontana.

[0] https://news.usc.edu/82959/diet-that-mimics-fasting-appears-...

[officelineback]

What are your results like? What did you hope to accomplish when you started, and what actually happened? Can you name some of the biggest benefits and some of the biggest pitfalls?

[sjcsjc]

I'm just trying not to die quite as soon as I otherwise might. I was and am fit an healthy (to the best of my knowledge).

In terms of results, my heart rate and BP have decreased (they weren't elevated previously). My weight remained the same as ever (around 10st, 65kg), which was my plan.

I've been fasting in other configurations for about 4.5 years now. I have a suspicion that I've been ill less (in the sense of colds etc) than pre-fasting, and that I recover more quickly, but I wouldn't take that as any kind of evidence. As soon as I can find some kind of cheap aging biomarker test, I'll start recording it regularly.

[Raphmedia]

Do you take supplements? I'm worried that fasting might cause my body to use all its micronutrients and me ending up with health issues because of it.

[Pete_D]

I am not a doctor. May I refer you to the following paper?

https://www.ncbi.nlm.nih.gov/pubmed/6859052 "Vigorous supplementation of a hypocaloric diet prevents cardiac arrhythmias and mineral depletion."

I wrote a comment a few months ago on fasting supplementation you may find interesting. https://news.ycombinator.com/item?id=12455415

Also seconding the recommendations to talk to a doctor before you do anything. I know that usually goes without saying, but it deserves emphasis given the article is about diabetes. As the current top comment points out, fasting can be very dangerous for diabetics.

[sjcsjc]

Oddly enough I an a doctor of sorts - qualified in medicine 25 years ago, but left immediately to do other things. Thanks for the link. I'm pretty sure I'm not hypocaloric. I make sure I eat enough during the 9 out of 14 days on which I eat, and I haven't lost weight. And yes, none of my comments refer to diabetes.

[oftenwrong]

Based on the parent's fasting regimen, and assuming they fast Monday to Friday, that would mean 9 days of normal eating between fasts. If you eat a normal healthy diet during those 9 days, you will be fine. Malnutrition takes more than 5 days to develop.

[sjcsjc]

Sorry forgot to mention that. No, I don't

[w23j]

Can you point to any instructions on how to do water only fasts? It has been surprisingly difficult to google. Most articles talk about intermittent fasting or some variation of fasting, where people drink a lot of juice!

In particular I would like to know is it really necessary to use laxatives? Or other supplements? Or do you just stop eating and then start slowly again 5 days later.

I have just done a 3 day water fast to give it a try. With mixed results.

[sjcsjc]

Hmm. Not really. I say water, btw, but I also drink black tea and occasional diet cokes. The point is no calories, or virtually none.

I would suggest starting gradually. Initially I think I did 48hr fasts. After a couple of years I upped to three days. Following Longo's stuff last year I moved to five.

No supplements. Definitely no laxatives ;-)

I don't start eating again particularly slowly. But I don't binge either.

The most amazing thing to me is that I don't get hungry. I haven't eaten since Sunday night, and I feel fine.

[jalopy]

I just searched "longo fasting" and this was the first result for me: "Fasting Mimicking Diet". https://prolonfmd.com/fasting-mimicking-diet/

It's a sales pitch so obviously needs caution here, but I'm curious - what do you know about a "fasting mimicking diet"? Is it at all effective?

[sjcsjc]

Yeah that irritates me somewhat. His research is great but I have my suspicions about the diet he's flogging. In my view the best way to mimic fasting is by not eating anything.

[edit] btw I suggest using google scholar rather than google. intermittent fasting, periodic fasting, prolonged fasting, calorie restriction. Lots of interesting stuff in there.

[w23j]

Ok, got it! Thanks a lot, this is really helpful! :)

[harrisreynolds]

This piece by Upton Sinclair is interesting: http://apache2.pum.edu.pl/~fasting/upton.pdf

He (obviously) was an author, not a nutritionist or medial professional. But he was a "fasting practitioner" and has an interesting perspective on this topic.

[hanklazard]

Do you have diabetes?

[sjcsjc]

No. I hope nothing I've said indicates that. And fwiw I concur with the suggestions in many other comments that diabetics should take medical advice before doing anything as drastic as I'm doing.

[baldfat]

1) People seriously think they are going to die when they fast for 3 days

2) Some people's blood sugar really is an issue and they can't traditionally fast without serious low blood sugar

3) People's understanding of how people lived 100 years ago let alone 10,000 years ago is minimal

[Someone]

1) People with diabetics may not surely die when they fast for 3 days, but it isn't something they can discard as a freak event, either.

2) For diabetics, blood sugar is an issue.

3) Many diabetics do quite well understand how diabetics _died_ 100 years ago, let alone 10,000 years ago ('young'. http://www.defeatdiabetes.org/diabetes-history/: "In 1897, the average life expectancy for a 10-year-old child with diabetes is about 1 year. Diagnosis at age 30 carries a life expectancy of about 4 years. A newly diagnosed 50-year-old might live 8 more years.")

[dukeluke]

4) Saying it's safe to do so opens you up to liability for other people's injuries from the diet.

[baldfat]

Don't start exercising without first speaking with your doctor. Now we are going to do 3 jumping jacks and then sit down in a chair.

[numbsafari]

You'd be amazed how many people show up for activities like that after having surgery. I had a woman come to a dance class with a knee brace on and ask if it was okay to participate even though she had had knee replacement surgery the week prior.

For someone with diabetes, an unmonitored and poorly planned fasting diet could be a recipe for disaster.

[JustSomeNobody]

Oh, come on. We have shards of pottery that tell us _exactly_ how people lived 10,000 years ago.

/s

[kleer001]

I know you're joking, but the evidence of diet from old teeth is pretty good.

[alex_duf]

>Assuming you go back to the roots and live in the forest. You are not going to eat every day...

Assuming you go back to the roots and live in the forest you're also a lot more likely to die.

[dualogy]

Yeah but not having a bite for a few days or even a week just simply won't be the cause

[manarth]

  not having a bite for a few days or even a week won't be the cause

Unless you're diabetic. Although in that case you were probably already dead.

[edwhitesell]

> People are advised not to try this without medical advice.

This is right after they talk about using it as a treatment for diabetes. If you're already diabetic, doing this as a treatment could have some risks.

[leereeves]

People with diabetes can develop diabetic hypoglycemia (which is very dangerous) if they fast.

[dkersten]

So test your blood sugar levels when you fast? I've started experimenting with intermittent fasting (36 hour fasts) and bought a test kit just to be sure even though I'm not diabetic. If you are, then you should definitely consult a doctor first and you're probably already testing your blood sugar.

[Filligree]

That's an interesting idea.

Where did you get the testing equipment? I tend to get very cold if I haven't eaten recently, if I'm not active -- always have -- and it would be fascinating to see if there's a connection.

[cowpewter]

Not sure where you're located, but the Walmart brand Reli-on testers are as accurate as any other brand you'll find on a pharmacy shelf, and have very reasonably priced test strips (glucose meters are like razor blades or printers, most of your cost will come from test strips, not the meter itself). I'm a T2 diabetic, and have a Reli-on Confirm. The device is only around $10 and the strips are ~$20 for a 50 pack or ~$35 for 100. It's a pretty good deal. Test strips the only thing I ever go to Walmart for anymore.

[mark-r]

Reli-on Prime user here. When I discovered that I could buy the test strips over-the-counter for less than the deductible on the ones my doctor prescribed, I switched and never went back. $18 for 100.

[sjcsjc]

I bought this for £12 a year ago. I see it's unavailable from that seller but you'll find it elsewhere. In the UK diabetics get these free. https://www.amazon.co.uk/gp/product/B004343VWS

[dkersten]

I got a similar one, also on Amazon, for a similar price. I'm not at home right now so can't check which one I got.

[godshatter]

When I was diagnosed with Type II, I bought the Bayer Contour Meter, which I have been very happy with.

https://www.amazon.com/gp/product/B01D0JTASA

[tonyedgecombe]

Isn't that just the case if they take too much insulin for their glycemic load? Persumably if they fast they would adjust their insulin levels (which they do for other reasons as well).

[jlg23]

"Diabetes mellitus is a chronic disease, for which there is no known cure except in very specific situations. Management concentrates on keeping blood sugar levels as close to normal, without causing low blood sugar. This can usually be accomplished with a healthy diet, exercise, weight loss, and use of appropriate medications (insulin in the case of type 1 diabetes; oral medications, as well as possibly insulin, in type 2 diabetes)." (emphases mine)

https://en.wikipedia.org/wiki/Diabetes_mellitus#Management

[ollysb]

I did this diet by myself a couple of years back and had great results (slightly modified, I did 1200 calories a day with a daily jog - works out at a net of roughly 800 calories). I found the first 4 days pretty uncomfortable but after that the diet was easy to follow. After a few days I was able to stop taking medication completely and ever since have been able to just use diet/exercise. I now do a top-up week about once every 6 months or so which I find is necessary to maintain the same level of glucose control (HBA1C is now 5.6, down from 8.1 at diagnosis).

[hanklazard]

I agree that fasting seems natural and as a doctor (though not an endocrinologist) I can tell you that it is generally safe for most people with what I would call "normal" physiology.

However, the discussion here is not about people with "normal" human physiology.

Remember what diabetes is: simplistically, it's the inability to properly regulate the glucose in the blood vs in the cells. Type I diabetes is an autoimmune condition that results in the destruction of the insulin-producing cells of the pancreas. Without insulin, blood glucose levels elevate but the cells of the body continue to starve.

Type I diabetics are basically trying to synthetically replace the activity that their pancreas would be performing through a combination of carefully regimented eating (including very close attention paid to carbohydrate) and blood glucose checks / insulin injections. Suddenly changing over to a fasting diet without careful supervision from a physician could be lethal for a type I diabetic.

I hope that helps clarify.

[leonroy]

We live in a pretty litigious society. Everything has to be caveated to cover the lowest common denominator. On top of that nutrition is a complex subject filled with a lot of mis-information. In this particular case fasting can be risky for those who are obese or have a lot of toxins in their fatty tissue.

From what I understand, pollutants in food (from pesticides and other sources) and in the environment which are not easily broken down are stored by the body in fat.

Fasting or sudden weight loss can cause these toxins to be released more rapidly than would otherwise be the case. This can tax your system pretty heavily if you're obese or have a higher incidence of pollutants in your body.

[oskarth]

It isn't risky. It's a liability thing.

Disclaimer: Not a doctor.

[azinman2]

So you state something as fact yet don't actually have the expertise to understand if that's even true? I'm not a medical doctor, but it seems fairly reasonable to me that people with diabetes shouldn't arbitrarily and radically change their diet because of an article they read on the internet...

[oskarth]

If you believe most doctors have expertise in nutrition and fasting you've not been paying attention.

It seems fairly obviously no one should arbitrarily and radically do anything just because someone told them to. There are a lot of special circumstances, but thankful there are useful concepts such as personal responsibility and common sense that have generally been useful in keeping humans alive for quite a while.

[cowpewter]

It's risky if you shoot up insulin every day, or take other drugs that have an effect on blood sugar. You could wind up in a hypoglycemic coma and die.

[miguelrochefort]

Very meta.

[ashark]

I know it shouldn't be a big deal to fast even for a few days, and I don't find hunger to be a problem, but I do find feeling very drunk-dizzy and incredibly tired starting around hours 14-16 to be a problem. That part definitely doesn't feel very healthy, and it's what's keeping me from making 1day+ long fasts part of my regular routine.

[leonroy]

I used to have the same problem. Probably low blood sugar if you're accustomed to a more carb rich diet. Switching to eating more healthy fats (olive oil, raw coconut oil, butter) and less sugar helped me with this particular problem.

[ashark]

Yeah, I'm doing salad-with-fats lunches now to hopefully aid the next attempt, and I rarely eat breakfast anyway but when I do it's already mostly fats 90% of the time (full-fat yoghurt with no added sugar + nuts).

Doubt I'd be able to go full-on keto and still eat dinner with my family, and the diet sounds pretty miserable anyway but I'm hoping this plus trying a fast again every week or so will get me past the problem.

Just want it to be known that, if you haven't tried it and don't know how you'll react, even a shortish fast may leave you feeling like you're an hour and a half in to a visit to a beer festival, which might be problematic if you have to actually do stuff that day. Maybe not doctor's-supervision-required, but consider doing the first couple attempts on days when you have no responsibilities (unfortunately much harder, IMO, since it's easier to fast when busy and not at home, but hey.)

[motoboi]

I'd like to give another perspective. When someone says people should not start exercising before seeing a doctor and without supervision, they are saying: you can die!

And people can really die if they "go back to the roots" and start running pursuing animals.

So, when someone says: don't this radical change in your nutrition habits, people should listen carefully.

[1_player]

Sorry, but that's not explanation.

[eivarv]

Whether it's natural or not is irrelevant [0] (though I get your larger point) - but explanations would have been helpful.

[0]: https://en.wikipedia.org/wiki/Appeal_to_nature

[SamBam]

Appeal to Nature is only a fallacy when discussing whether something is good or not, not whether or not it is healthy or safe.

The argument that, say, "walking for six hours a day is unlikely to be dangerous, since early humans did so" may or may not be factually correct, but it's a reasoned argument.

[eivarv]

You're not really correct: There are, for instance, poisons and venoms in nature.

Additionally, the example argument you make isn't an appeal to nature; The argument is based upon what early humans did (not nature, or whether something is "natural"), and is a resonable conjecture.

What I had an issue with in the parent comment was "Fasting is kinda natural" - which doesn't say anything about fasting in and of itself.

[Shivetya]

Because for diabetics your diet and changes to can lead to wild swings of your glucose levels and would require much more diligent monitoring, something individually is very hard to do while asleep. Sleeping is not a good time to have a low sugar even and it can happen quickly and you just don't wake up from it.

purely anecdotal but my mother has seen high levels before going to bed only to wake up dangerous low. Or the fun good level and suddenly in the morning you are at 300+. Ask three doctors at hospital and get three different opinions.

No, don't do it at home and don't do it unless monitored by a health care professional who knows how to respond.