Is Fasting for Weight Loss Safe?

Is Fasting for Weight Loss Safe?
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The reasons why fasting longer than 24 hours, and particularly three or more days, should only be done under the supervision of a health professional and preferably in a live-in clinic.

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Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

Although fasting for a week or two can actually interfere with the loss of body fat, eventually, after the third week of fasting, fat loss starts to overtake the loss of lean body mass in obese individuals. But is it safe to go that long without food?

Proponents speak of fasting as a cleansing process, but some of what they are purging from their body are essential vitamins and minerals. Heavy-enough people can go up to 382 days without calories, but no one can go even a fraction of that long without vitamins. Scurvy, for example, is diagnosable within as few as four weeks without any vitamin C. Beriberi, thiamine (vitamin B1) deficiency, may start out even earlier in fasting patients, and once it manifests can result in brain damage within days—which can eventually become irreversible.

Even though fasting patients report problems such as nausea and indigestion taking supplements, all of the months-long fasting cases I’ve mentioned in the last few videos were given daily multivitamins and mineral supplementation as necessary. Without supplementation, hunger strikers, and those undergoing prolonged fasts for therapeutic or religious purposes (like the Baptist pastor hoping to “enhance his spiritual powers for exorcism”) have ended up paralyzed, comatose, or worse.

Nutrient deficiencies aren’t the only risk. Reading about all the successful reports of massive weight loss from prolonged fasting in the medical literature, one doctor decided to give it a try with his patients. Of the first dozen he tried it on, though, two died. Now, in retrospect, both the two patients that died started out with heart failure and were on diuretics. Fasting itself produces a pronounced diuresis, meaning loss of water and electrolytes through the urine. And so, it was the combination of fasting on top of the water pills that likely depleted their potassium and triggered their fatal heart rhythms. The doctor went out of his way to point out that both of those who died started out in severe heart failure, and “both had improved greatly whilst undergoing starvation therapy.” Small consolation, since they were both dead within a matter of weeks.

Not all therapeutic fasting fatalities were complicated by concurrent medication use. “At first he did very well and experienced the usual euphoria…[his] electrolytes remained [fine], but in the middle of the third week…he suddenly collapsed and died. This line of treatment is certainly tempting because it does produce weight-loss, and the patient feels so much better, but the [whole killing people thing] must make it a very suspect line of management.”

Contrary to the popular notion that the heart muscle is specially spared during fasting, the heart appears to experience similar muscle wasting. This was noted in the victims of the Warsaw ghetto during World War II in a remarkable series of detailed studies carried out by the ghetto physicians, before they themselves succumbed. In a case entitled “Gross Fragmentation Of Cardiac Fiber After Therapeutic Starvation For Obesity,” a 20-year-old woman successfully achieved her ideal body weight after losing 128 pounds fasting for 30 weeks. After a breakfast of one egg, she had a heart attack and died. On autopsy, the muscle fibers in her heart showed evidence of widespread disintegration. The pathologists suggested that fasting regimens “should no longer be recommended as a safe means of weight reduction.”

Breaking the fast appears to be the most dangerous part. After World War II, as many as one out of five starved Japanese prisoners of war tragically died following liberation. Now known as “refeeding syndrome,” multiorgan system failure can result from resuming a regular diet too quickly. See, there are critical nutrients, such as thiamine and phosphorus, that are used to metabolize food. So, in the critical refeeding window, if too much food is taken before these nutrients can be replenished, demand may exceed supply. And whatever residual stores you still carry can be driven down even further, with potentially fatal consequences. That’s why rescue workers are taught to always give thiamine before food to victims who had been trapped or otherwise unable to eat. Thiamine is responsible for the yellow color of “banana bags,” a term you might have heard used on medical dramas, used to describe an IV fluid concoction often given to malnourished alcoholics to prevent a similar reaction. Anyone “with negligible food intake for more than five days” may be at risk of developing refeeding problems.

Medically-supervised fasting has gotten much safer now that there are proper refeeding protocols, we know what warning signs to look for, and we now know who shouldn’t be fasting in the first place (such as those with advanced liver or kidney failure, porphyria, uncontrolled hyperthyroidism, and pregnant and breastfeeding women). The most comprehensive safety analysis of medically-supervised, water-only fasting was recently published out of the True North Health Center in California. Out of 768 visits to their facility for fasts up to 41 days, were there any adverse events? Yes, 5,961 of them! But most were mild known reactions to fasting, such as fatigue, nausea, insomnia, headache, dizziness, upset stomach, and back pain. They report only two serious events, and no fatalities.

Fasting longer than 24 hours, and particularly three or more days, should only be done under the supervision of a physician and preferably in a live-in clinic. In other words, don’t try this at home. This is not just legalistic mumbo-jumbo. For example, normally your kidneys dive into sodium conservation mode during fasting, but should that response break down, you could rapidly develop an electrolyte abnormality that may only manifest with non-specific symptoms like fatigue or dizziness, which could easily be dismissed until it’s too late.

The risks of any therapy must be premised on the severity of the disease. The consequences of obesity are considered so serious that effective therapies could have “considerable acceptable toxicity.” For example, many consider major surgery for obesity to be a justifiable risk. But the key word is effective.

Therapeutic fasting for obesity has been largely abandoned by the medical community not only because of its uncertain safety profile, but its questionable short- and long-term efficacy. Remember, for a fast that only lasts a week or two, you might be able to lose as much body fat or even more on a low-calorie diet, than a no-calorie diet.

Please consider volunteering to help out on the site.

Image credit: Jean Fortunet via wikimedia. Image has been modified.

Motion graphics by Avocado Video

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

Although fasting for a week or two can actually interfere with the loss of body fat, eventually, after the third week of fasting, fat loss starts to overtake the loss of lean body mass in obese individuals. But is it safe to go that long without food?

Proponents speak of fasting as a cleansing process, but some of what they are purging from their body are essential vitamins and minerals. Heavy-enough people can go up to 382 days without calories, but no one can go even a fraction of that long without vitamins. Scurvy, for example, is diagnosable within as few as four weeks without any vitamin C. Beriberi, thiamine (vitamin B1) deficiency, may start out even earlier in fasting patients, and once it manifests can result in brain damage within days—which can eventually become irreversible.

Even though fasting patients report problems such as nausea and indigestion taking supplements, all of the months-long fasting cases I’ve mentioned in the last few videos were given daily multivitamins and mineral supplementation as necessary. Without supplementation, hunger strikers, and those undergoing prolonged fasts for therapeutic or religious purposes (like the Baptist pastor hoping to “enhance his spiritual powers for exorcism”) have ended up paralyzed, comatose, or worse.

Nutrient deficiencies aren’t the only risk. Reading about all the successful reports of massive weight loss from prolonged fasting in the medical literature, one doctor decided to give it a try with his patients. Of the first dozen he tried it on, though, two died. Now, in retrospect, both the two patients that died started out with heart failure and were on diuretics. Fasting itself produces a pronounced diuresis, meaning loss of water and electrolytes through the urine. And so, it was the combination of fasting on top of the water pills that likely depleted their potassium and triggered their fatal heart rhythms. The doctor went out of his way to point out that both of those who died started out in severe heart failure, and “both had improved greatly whilst undergoing starvation therapy.” Small consolation, since they were both dead within a matter of weeks.

Not all therapeutic fasting fatalities were complicated by concurrent medication use. “At first he did very well and experienced the usual euphoria…[his] electrolytes remained [fine], but in the middle of the third week…he suddenly collapsed and died. This line of treatment is certainly tempting because it does produce weight-loss, and the patient feels so much better, but the [whole killing people thing] must make it a very suspect line of management.”

Contrary to the popular notion that the heart muscle is specially spared during fasting, the heart appears to experience similar muscle wasting. This was noted in the victims of the Warsaw ghetto during World War II in a remarkable series of detailed studies carried out by the ghetto physicians, before they themselves succumbed. In a case entitled “Gross Fragmentation Of Cardiac Fiber After Therapeutic Starvation For Obesity,” a 20-year-old woman successfully achieved her ideal body weight after losing 128 pounds fasting for 30 weeks. After a breakfast of one egg, she had a heart attack and died. On autopsy, the muscle fibers in her heart showed evidence of widespread disintegration. The pathologists suggested that fasting regimens “should no longer be recommended as a safe means of weight reduction.”

Breaking the fast appears to be the most dangerous part. After World War II, as many as one out of five starved Japanese prisoners of war tragically died following liberation. Now known as “refeeding syndrome,” multiorgan system failure can result from resuming a regular diet too quickly. See, there are critical nutrients, such as thiamine and phosphorus, that are used to metabolize food. So, in the critical refeeding window, if too much food is taken before these nutrients can be replenished, demand may exceed supply. And whatever residual stores you still carry can be driven down even further, with potentially fatal consequences. That’s why rescue workers are taught to always give thiamine before food to victims who had been trapped or otherwise unable to eat. Thiamine is responsible for the yellow color of “banana bags,” a term you might have heard used on medical dramas, used to describe an IV fluid concoction often given to malnourished alcoholics to prevent a similar reaction. Anyone “with negligible food intake for more than five days” may be at risk of developing refeeding problems.

Medically-supervised fasting has gotten much safer now that there are proper refeeding protocols, we know what warning signs to look for, and we now know who shouldn’t be fasting in the first place (such as those with advanced liver or kidney failure, porphyria, uncontrolled hyperthyroidism, and pregnant and breastfeeding women). The most comprehensive safety analysis of medically-supervised, water-only fasting was recently published out of the True North Health Center in California. Out of 768 visits to their facility for fasts up to 41 days, were there any adverse events? Yes, 5,961 of them! But most were mild known reactions to fasting, such as fatigue, nausea, insomnia, headache, dizziness, upset stomach, and back pain. They report only two serious events, and no fatalities.

Fasting longer than 24 hours, and particularly three or more days, should only be done under the supervision of a physician and preferably in a live-in clinic. In other words, don’t try this at home. This is not just legalistic mumbo-jumbo. For example, normally your kidneys dive into sodium conservation mode during fasting, but should that response break down, you could rapidly develop an electrolyte abnormality that may only manifest with non-specific symptoms like fatigue or dizziness, which could easily be dismissed until it’s too late.

The risks of any therapy must be premised on the severity of the disease. The consequences of obesity are considered so serious that effective therapies could have “considerable acceptable toxicity.” For example, many consider major surgery for obesity to be a justifiable risk. But the key word is effective.

Therapeutic fasting for obesity has been largely abandoned by the medical community not only because of its uncertain safety profile, but its questionable short- and long-term efficacy. Remember, for a fast that only lasts a week or two, you might be able to lose as much body fat or even more on a low-calorie diet, than a no-calorie diet.

Please consider volunteering to help out on the site.

Image credit: Jean Fortunet via wikimedia. Image has been modified.

Motion graphics by Avocado Video

Doctor's Note

Fasting for a week or two can actually interfere with the loss of body fat? If you missed it, check out my last video Is Fasting Beneficial for Weight Loss? and for more background, Benefits of Fasting for Weight Loss Put to the Test.

What’s the best way to lose weight? I wrote a whole book about it! Pre-order How Not to Diet.

Next I turn my focus to intermittent fasting—stay tuned:

If you haven’t yet, you can subscribe to my videos for free by clicking here.

155 responses to “Is Fasting for Weight Loss Safe?

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  1. This reminds me to never take up fasting unless live-in supervised at True North Clinic. The best way of eating I know of is to eat all you want WFPB, and forget about calorie counting, electrolytes, vitamins and such.

    1. Yes, WFPB with some cheats here or there for various occasions has worked GREAT for me nearly five years now. Wish I’d started many years sooner. Cannot fathom going back to the old ways and all the suffering it brings.

      I will fast through lunch or a breakfast now and then, for travel mostly, but not a whole day–I’ve got no real extra weight to lose!

    2. Dan,

      I agree.

      Plant based whole food eating has worked for me, my husband, and my brother. We also exercise, probably moderately. A lot of this exercise is yardwork, gardening, housework, cooking, laundry, etc. In the winter: snow shoveling! (I like to say that some people go to the gym, and we go into our backyard.)

      I can’t imagine fasting; I like to eat too much. To me, fasting at all seems like a High Intensity Interval Training by sprinting across the road in front of oncoming traffic, the closer all the better to run faster, right? Maybe works for some, but others will suffer a bad outcome.

      1. Dr J, I agree with you and Dan. In my own case, weight slid off quickly the first month I had let go of animal products. There are benefits to fasting though, and, different fasting formats that work. Dr Mirkin and his wife practice alternate day fasting, as well as a type of intermittant fasting. Some discussion is found at this link:
        https://www.drmirkin.com/nutrition/why-intermittent-fasting-works.html

        I noticed a number of people asking in the forum about related topics such as 5:2 fasting, intermittant fasting, reduced calorie plans etc. Dr Greger is addressing these topics and more in upcoming videos. At this link, scroll down to find the videos scheduled for upcoming weeks.

        https://nutritionfacts.org/2019/09/26/final-fasting-webinar-and-new-dvd/

        1. I’ve been an intermittent faster for the last 3 years now, and although I didn’t really need to lose any weight, I’ve lost 14 pounds eating this way. I started this type of eating for the metabolic boosts it gives you, as the first link discusses, and I did not give up eating animals nor fats. In fact, I eat much more fat than before I started eating this way. I’m not a keto or paleo follower; I just eat in moderation. . .probably leaning more toward a Mediterranean diet.

          1. Suz,

            I wish the best for you, but I will tell you that my father has been doing intermittent fasting while eating animal products and fats, but he did end up having a heart attack and now is being looked at for kidney cancer, so being low in weight is not protection. My mother never gained weight and she was a moderation eater, but she died at 53 from breast cancer. I am saying it because even one serving of saturated fats can paralyze your endothelials and people can die from a heart attack even without having blocked arteries just from not having vasodilation.

          2. I also am an intermittent faster and eat very similar to you,Suz. I also have increased my good fats. I have lost 12 lbs that I needed to lose and am very happy.

            1. Blue Moon,

              That is one way to lose weight, and if, by fats, you mean nuts, seeds and avocado, then, good for you.

              If you are doing animal products and coconut oil, then watch out.

              I will add that my skinny mini step-mother who does intermittent fasting and eats fats and animal products had a stroke.

              Perfect weight looks better but doesn’t mean no health risks.

              The people around me are not WFPB at all. It isn’t my seriously obese SAD diet friends calling me with serious health problems.

              That day may come, but my 400 pound friend has outlived a lot of my skinny mini relatives.

            2. What do you mean by ‘good fats’?

              There is solid scientific evidence about which fats are bad for us in significant amounts and which are relatively healthier, eg the summary in this paper
              https://ahajournals.org/doi/full/10.1161/CIR.0000000000000510

              However, there are very voluble quacks and cranks on the internet and YouTube who try to convince other people that bad fats are in fact ‘good fats’ And that eating lots of these fats is heart healthy.

          3. Skinny people have heart attacks, strokes, alzheimer’s, cancer, etc., too. It’s what you eat above and beyond anything else. Your dress size doesn’t determine the health of your body.

              1. Undoubtedly, Barb. However, if you’re keeping your waistline down by eating a diet high in saturated animal fats, I wonder how much those risk factors would go down and what other ones might go up. I would say if someone got to their goal weight eating this way, take the gain and change your diet to a more healthful one that also maintains your weight loss so you get the best of both worlds.

      2. “To me, fasting at all seems like a High Intensity Interval Training by sprinting across the road in front of oncoming traffic, the closer all the better to run faster, right? Maybe works for some, but others will suffer a bad outcome.”

        Lol.

    3. I totally agree, Dan. This has been my experience and it’s had amazing outcomes. I don’t even know why anyone would want to go to a live-in supervised fasting retreat even at Truth North given that it obviously isn’t healthy for our bodies to starve. I’d rather people gravitate toward clinics or retreats for WFPB eating. So what are the huge benefits that would justify anyone even doing a properly supervised fast? I assume a video is coming out to let us know if all the health claims are true. So far it’s not looking so good. I’m especially curious about the consequences to our good bacteria.

        1. Tom, certainly fasting as an effective cancer treatment would be worthwhile, but as a regular practice in healthy people, that’s where I’m wondering what benefits might exist that would justify doing something that is clearly harmful to us in a healthy person? I’m sure we’ll see more on the claims of the benefits besides weight loss in videos to come. Looking forward to them.

  2. The only way to stay slim and in perfect health is to eat all day long as an emotional eater. This is what every living creature does.
    For the last 5 decades almost every day I have gone for a walk I see squirrels, birds, insects, rabbits, deer etc. All they do all day long is eat for free and run around and get exercise for free. They only eat natural foods.
    And because of this I have never seen one of these living creatures that is not in perfect health, weight and shape. As far as vitamins and supplements, they seem to be thriving by eating from the same so called nutrient depleted soil without needing any vitamins and supplements.

    1. Yerky,

      I’ve seen some pretty scruffy squirrels, birds, coyotes, etc. Some are downright mangy and skeletal. They do suffer from ailments. But it’s true that I haven’t seen any overweight ones — except bears, just before they hibernate.

        1. I’ve never seen an overweight wild animals. What season were you seeing them? Animals store fat for winter as they’re supposed to. Also you may mistake pregnant wildlife for being overweight. If an animal has a parasite, their bellies can become bloated, too. Sadly, animals living in deforested cities relying on garbage scraps probably suffer various consequences, heartbreakingly.

          1. Just a special mention for our little possum friends. Sadly, they’re unable to store fat for winter as they originated from the southern states but humans, disruptive as they are, brought them here. So they suffer a great deal during winter but have managed to survive through the ages due to how incredibly smart they are. If you see a possum out in snowy or extreme weather, they’re desperate, it’s ok to put some cat or dog food out to help these poor little babies, also having places for shelter is incredibly helpful to them because they can’t dig and such like other animals to create their own burrows and things. Possums are actually very peaceful animals and are more likely to back down in a confrontation, if they show their teeth it’s because they’re terrified, not mean. They’re actually incredibly good to have around because they eat ticks!! I take care of spayed/neutered/released feral cats and even though I’m by forest, they never get ticks probably because we have a good possum population.

    2. It’s against the law of nature to fast. If you are going to get complicated and trick your body and nature, then nature will trick you back
      and win 100% of the time.

      1. “It’s against the law of nature to fast. If you are going to get complicated and trick your body and nature, then nature will trick you back
        and win 100% of the time.”

        I absolutely agree with this statement. There’s enough evidence to prove that it’s unnatural for us and thus unhealthy and dangerous. If you need to supplement to survive something, it isn’t natural for your body. Being natural as opposed to going against nature is always going to be optimal.

        1. People might use the B12 argument for my above statement, but in actuality we would be getting our B12 just like every other herbivorous animal naturally does, through dirt and water, but it’s not safe for us in part due to the industrial era and I’m not sure our immune systems have evolved to handle it like other animals as we got pretty indoorsy throughout the years.

          1. Is it, though? If the evidence shows it harms us, then that makes it an unnatural diet for us, no? Same with a ketogenic diet, for example… the evidence shows it harms us, so therefore it is unnatural for us to do so, correct? How would it then be a false statement to say something like “eating a diet high in saturated fat and animal protein goes against our nature?”

            Whereas if you were basing it off of observation like “our ancestors ate meat for a time so therefore it’s natural for us to” that’s different because it’s not starting with the evidence but rather assumption.

    3. “The only way to stay slim and in perfect health is to eat all day long as an emotional eater.”
      – – – – –

      That was meant to be a funny-haha, right Jerky-Yerky? The “only” way to stay slim? “Eat all day long”? Nobody I know is an emotional eater….but then I don’t know many fatties either.

      Where are your links to the god-almighty scientific evidence?

      Why not do what the doggies do (besides licking their crotches and smelling those of humans)? They eat their own vomit. And many animals eat their own offspring. Would you do that?

  3. That graph at the end states that you can lose 600g of fat on calorie restriction diet per day… isn’t that too much? That’s like 5400 kcal worth of fat

    1. When my patients switch to a WFPBD they tend to drop 500-1200 cal per day of “body energy”…. when NO oil they drop about 800-1500 per day, that comes back to zero over 5-6 months when starch levels are negotiable and food preferences are better

      1. Sorry, didn’t quite get that, what do you mean by “starch levels are negotiable and food preferences are better“? I thought that you loose the same amount of “body energy” as the amount of calories you restrict in comparison to how much is needed to maintain your body weight and that over 1000 kcal per day seems a lot

        1. Dear Anna,

          Thanks for your query. What I was meaning to say is that low-fat whole foods plant based diet allow patients to mobilise their fat as an energy source the source. The weight reduction in body fat is quite marked. If you calculate Changes in body compartment, this is where I get my calculations from in relationship to calories burned and from which source. Maintaining grains and tuberous foods seems to be a way of keeping calories High enough to maintain weight which can be a problem in the long term. Sent from Dr Patterson Stark

  4. Another issue with fasting more than 12-24 hours as pointed out by Nathan Pritikin https://www.youtube.com/watch?v=BcHHDmuyPv4 is when your glycogen stores start running low, the liver starts dumping a bunch of fat in the bloodstream. This results in a diabetic blood glucose spike upon reintroduction of carbs, the same response as those eating high fat keto diets.

  5. Good video. I do wish Dr Greger would give some advice on what to do to stay safe if you’re doing a 3 day or more fast. I sometimes participate in a Buddhist fast called Nyungne that lasts several days.

    1. Max,

      I think the advice is to not fast without supervision. But there were things listed such as making sure to get your electrolytes and vitamins and monitor your blood pressure and pulse and know your health.

      I had a pastor end up in the ER after a fairly short fast. As a congregation, we were doing a lot of fasting around that time. Most of it was short-term, a few days at a time. We had a worship service after a long weekend of fasting and my pastor didn’t move at the end. His eyes were open, but he was not responding to anyone. People were talking with him and he didn’t speak and didn’t move until after the ambulance came. He was low in electrolytes, but looking at the vitamin list, some of those can cause major problems and we were fasting so often that I don’t know if there might have been a cumulative effect.

      Anyway, I passed out and hit my head on concrete that year as part of fasting and what I saw was that, in the Christian communities, the teaching about fasting started to include, “If you have blood sugar problems, modify the fast this way…” “If you have heart problems….”

      Some people switched to juice fasting, for instance. Mimicking fasting would be another alternative.

      We were fasting for more spiritual reasons and I remember the leadership telling me that I should not do water fasting anymore and I agreed.

      I had a few falls with my head hitting concrete and I know that I had blood sugar issues.

    2. The description of the video (found above under the video itself) addresses this very point

      ‘The reasons why fasting longer than 24 hours, and particularly three or more days, should only be done under the supervision of a health professional and preferably in a live-in clinic’

      In other words, unless you are supervised by a competent health professional. it is probably risky – especially if you have pre-existing health issues.

    3. Rest and stay close to the floor. Never get up quickly. Count to ten before standing. Your greatest risk is fainting and hitting your head. A good reference book is Fasting and Eating for Health by Joel Fuhrman

  6. HOWEVER, You can fast from food while ingesting an electrolyte water (water + salt + k). In that scenario, seems like a lot of the dangers are mitigated perhaps…

    1. zzz, I asked my doctor about it and he said he adds just a bit of an electrolyte powder (like gatorade) to his water bottle once a day. He had no other concerns but then I have had bloodwork etc recently.

  7. PERPLEXED.
    With an abundance of credible literature published over decades demonstrating the remarkable health benefits (including long-term weight reduction) and muscle (protein) sparing effects of extended water fasting, I am perplexed at this conclusion.

    https://www.dietdoctor.com/does-fasting-burn-muscle (Does fasting burn muscle?)

    https://www.ncbi.nlm.nih.gov/pubmed/22386777 (The effect of prolonged fasting on levels of growth hormone-binding protein and free growth hormone.)

    1. The ‘dietdoctor’ is a well-known low carb crank and not to be relied upon for sound evidence based advice.

      The ‘prolonged fasting’ discussed in the paper you link to is referring to a 24-hour fast only. It is termed ‘prolonged’ to differentiate it from an overnight fast.

  8. BRIAN L – I’m with you. I’ve recently been diving into the literature on fasting and it seems to have so much history and so many benefits. That said, I do think liquid minerals + sea salt + potassium has a place if you are doing more than 24 hours. Certainly, beyond the 3 days I usually do, I would either use ProLon or get supervision.

    Before fasting – knowing how to refeed is CRUCIAL, and I am glad that this video highlights that. You can make yourself VERY SICK if you don’t know what to do at the end of a fast – even a few days.

    Knowing yourself and your limitations are also key to the entire equation. It certainly isn’t for everyone.

  9. I am curious then why other WFPB doctors like Michael Klapper celebrate and promote water fasting as a means to weight loss. A 3-day water fast he likens to a “Carwash for the Body” and supports anyone doing at home over a weekend. Anything longer than that he advises medical supervision.

    So confused where the real truth lies on this. I wanted Dr. Greger to be my one-stop shop for all things WFPB but I am not so sure anymore!

    1. Suanne.
      My reaction is just the opposite. I am thankful that Dr. Greger has the courage to speak out against the rather blaise attitude among some WFPB doctors regarding the risks of ‘do it yourself’ fasting. He presents plenty of evidence for his conclusions.

      But note that Dr. Greger said “and particularly more or more days”.

      What ever happened to “Primum non nocere (First do no harm)”?.

      1. Gengo,

        I am with you.

        I don’t just want to hear the benefits.

        I also want to hear the risks presented in a dispassionate way.

        Dr Greger has not disappointed me at all.

        I have watched so many other doctors that I wondered if he could say anything the others hadn’t said in their longer formats but he did in the Keto video and in this one.

        With most of the videos, I came here brand new without any understanding and someone at another site tried to get me to admit that Dr Greger is doing a more entertaining process and the doctor he followed was more thorough is what he said, but Keto and intermittent fasting were his favorite doctor’s main topics and I did watch that doctor, too, but she missed major things in both topics and Dr Greger’s video process may be closer to Cliffs Notes than that doctor, but she missed 100% of the opposing arguments and after 2 years of watching videos on those topics, Dr Greger’s entertaining process ended up telling me all I needed to know.

    2. The only real difference between the two on this particular point is that Klaper recommends medical supervision for fasts longer than 3 days while Greger recommends medical supervision for fasts lasting 3 days or more.

      Note also that this video is only about the safety of water based fasting. It is not a video about whether people should or should not fast for weight loss.

      1. Actually Dr. Greger said fasting longer than 24 hours should be medically supervised (note the two commas):

        “Fasting longer than 24 hours, and particularly three or more days, should only be done under the supervision of a physician”

        1. Good point gengo. Thanks.

          This is particularly true if we have pre-existing health conditions and risk factors. And even some common genetic conditions can predispose us to increased risk. My wife for example has low potassium levels and ceasing intake of potassium rich foods would be quite risky.

  10. The re-feeding part is something I never took seriously. Nobody explained it this way.

    “Breaking the fast appears to be the most dangerous part. After World War II, as many as one out of five starved Japanese prisoners of war tragically died following liberation. Now known as “refeeding syndrome,” multiorgan system failure can result from resuming a regular diet too quickly. See, there are critical nutrients, such as thiamine and phosphorus, that are used to metabolize food. So, in the critical refeeding window, if too much food is taken before these nutrients can be replenished, demand may exceed supply. And whatever residual stores you still carry can be driven down even further, with potentially fatal consequences. “

  11. Well, this is not all the info on fasting for sure. Many recommend something like Himalayan Pink salt added to water to guard against electrolytic depletion and for minerals that help your body deal with the stress of fasting. Dr Jason Fung has great insights in his book “The Obesity Code”. Highly recommended. I have had no issues with fasts up to 48 hours. Feeling great too…! Knowledge is power…!!!

    1. Doug,

      This is the third of at least 9 videos about fasting; they are listed under the Doctor’s Note. So this one video will not have all the info on fasting, for sure.

      And when you make comments such as “Many recommend,” do they provide scientific research evidence to support these recommendations? The videos presented on this site are based on nutrition science research articles published in peer-reviewed journals, the gold standard. I have the same questions about Dr. Jason Fung — does he have good scientific evidence to support any recommendations, or even observations, in his book?

      I agree that knowledge is power — but I prefer my knowledge to be evidenced based. Someone telling me something, absent more (actually, much more — evidence, with scientific research articles to support what they say) is not helpful to me.

      1. Dr. J,
        Of course I agree with your statement, But have to say that in my view, all knowledge (justified true belief) is evidence based. If there is none, then there is no knowledge, merely belief :-)

        1. Genko Gashuka – “Evidence based” on this site, which is a scientifically-based site, in this case means evidence obtained via the SCIENTIFIC METHOD. This site is a SCIENTIFIC METHOD based site. Here is the definition of the SCIENTIFIC METHOD:
          ” a method of procedure that has characterized natural science since the 17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses.
          “criticism is the backbone of the scientific method”

          “Measurement” is a critical component of the SCIENTIFIC METHOD as is the ability to REPEAT RESULTS.

          The SCIENTIFIC METHOD is much, much more than one’s simplistic observations of the world around them.
          Thank you.

          1. Wow, lighten up Ruth!

            I said that “OF COURSE, I AGREE” with Dr. J’s statement. It just happened I found the phrasing “but I prefer my knowledge to be evidenced based” a bit humorous, analogous to saying “I prefer my facts to be true”. As indicated by the use of “:-“, my comment was lighthearted, not critical.

            It remains a mystery to me why you thought I was in need of your LOUD mini-lecture, but I am sure you had your reasons.

            1. gengo-gakusha,

              It’s possible that Ruth misconstrued your statement, if she has been subjected, as I have, ad nauseum, to smug comments such as: “There are other ways of knowing than through the scientific method,” or “Science isn’t the only way to gain knowledge of the world,” etc.

              I always want to know: What other ways? And how can you verify your knowledge? Can it be used to make predictions (eg, as to how the world works)? Is this knowledge useful? How would you know? Can you use it to build radios, or televisions, or buildings, Etc

              1. Well there is more to all things than building radios and the functionality of things. There’s psychological and spiritual which of course not everyone believes in (the spiritual). The only way to make a provable statement is through the scientific method, that isn’t to say that the only truths exist if they can be proven to us.

              2. Dr. J,
                I didn’t realize you’ve been subjected to a barrage smug comments. I certainly do not belong in that company as I read many of your comments and appreciate them.

                It would not be the first time my impulsive humor has been misconstrued and landed me in hot water.

    2. >>>Himalayan Pink salt
      You would take in mostly salt. It’s generally ~95-97% NaCl. To get enough of the other minerals you’d have to eat so much of it you’d probably from ingesting too much sodium. It also has a number of undesirable and toxic elements.

      https://themeadow.com/pages/minerals-in-himalayan-pink-salt-spectral-analysis
      https://www.mcgill.ca/oss/article/health-and-nutrition-quackery-you-asked/himalayan-pink-salt

      Let’s try to stick with actual science.

    3. Deb

      Slightly off-topic but Nathan Pritikin reported that when working for the (US) air force he had access to a wide range of classified information. As well as noting that deaths from chronic disease plummeted in WW2 in those countries that experienced strict rationing, he referred to concentration camp survivors.

      He said that the Nazi doctors were found to have kept meticulous records. And inmates who entered the camps with hypertension, diabetes, heart disease etc and survived, came out the other end with their chronic diseases cured. This was extreme calorie restriction though not actual water fasting.

      https://www.youtube.com/watch?v=CT8K6NcAigo&t=2193s

    4. Doug

      Many recommend Himalayan salt – but that’s mainly because they sell it or because they believe the hype of people who sell it. It’s really just a way of making ridiculous amounts of money by selling prettily-coloured salt.

      And Fung is just another low carb guru who is idolised by other low carbers because he tells them what they want to hear and is a qualified medical professional.. Not everybody is convinced by his claims though eg this professional dietitian
      https://www.evolvedsportandnutrition.com/blog/why-you-should-think-twice-before-taking-dietary-advice-from-anyone-other-than-a-dietitian

      .His claims need to be rigorously fact-checked rather than just accepted on blind faith..

  12. Both Dr. Joel Fuhrman and Dr. Michael Klaper who have clinically fasted patients say fasting without medical supervision for up to 3 to 5 days (latter if healthy) is safe, not one day. The difference is the pre and post fast diet, something not discussed in the video. This video unlike most of Michael’s videos has little relevance or value to me. I have fasted over 10 days without medical supervision many times safely. 21 days was my longest. As long as you understand the risks and how to manage it, it can be done safely.

    1. Krefcenz

      This video was about the risks and that depends on people’s age and health and things like electrolytes and vitamin levels, and those were the topics Dr. Greger used.

      I have passed out before the end of 3 days of fasting and I have seen people end up in the ER within that length of time.

      Was it pre-fast diet or health issues, who knows, either way, this video is accurate about the risks. The fact that people die is something most people may not even know. I did know that someone died after a 21-day fast, but I didn’t know the rest.

      Would you have him not tell people about the real risks?

    2. Are you talking about 21 day water only fasts? Seems very foolish to me. IN any event, good luck with that. I see no reason to take such risks.

      >>>Both Dr. Joel Fuhrman and Dr. Michael Klaper who have clinically fasted patients say fasting without medical supervision for up to 3 to 5 days (latter if healthy) is safe, not one day.

      I’ll stick with Dr. Greger on this one. I like Dr. Fuhrman generally but think the recommendation unwise.

      1. I think we have to consider who is likely to be taking the fasting advice.. Dr Greger draws an enthusiastic crowd with all different health issues going on, from elite athletes to the very sick. And some have not seen their doctor in a long time. It’s only reasonable that he would take a conservative stance on fasting where there is an element of risk for those are walking around with untreated health issues who want to try fasting.

        On the other hand, I am not interested in hearing infomercials for grossely over-priced ‘supervision’ facilites peddling testing, supplements and water.
        Talking to our own doctors is best.

        1. Barb,

          Yes, this audience is so mixed that he is wise to be conservative.

          Particularly when fasting has become so popular and most people are not doing it supervised.

          Also, I already watched so many things from Fung, Seyfried, Berg, Klaper, Fuhrman and, Goldhammer and, on my own, I looked at PubMed and read about a woman who died after a 21 Day water fast, but Dr Greger just listed several deaths and things like paralysis and brain damage from doing the process wrong and he is the first doctor who mentioned those things and I have been watching everything for so long.

          I fasted with churches for years and did all of it entirely wrong and when they said, “Break your fast gently, they mentioned digestive problems that I don’t get so I ignored them. Nobody said if you don’t have enough vitamins in your system you could die. People were doing 40 day water fasts unsupervised and people were having problems, but this video might save people’s lives.

          The cancer community has people trying to do 70-day fasts and I know a woman who was in a church which was more like a cult and they were very controlling and they did corporate 70-day water fasts.

          More than one person mentally broke down with it.

          1. I have watched so many videos making almost miraculous claims about fasting.

            This is the first one which put the risks in perspective.

            I said the same thing with the Keto and Diabetes video.

            Dr Greger goes one step farther than the other doctors and adds in the risks.

            I appreciate that so much!

        2. “It’s only reasonable that he would take a conservative stance on fasting where there is an element of risk for those are walking around with untreated health issues who want to try fasting.”

          In being totally honest, that sounds more like rationalizing Dr. Greger’s bottom line to fit your take on fasting. Seems his stance is pretty legit based on the evidence to me more than concern for a broad audience.

          1. Don’t be ridiculous S. geesh. what garbage. I dont need to rationalize my view on anything. I have spent the last year with my nose in the studies on pubmed. Have you? I am saying that Dr Greger in speaking to the public, will consider his audience in what he advises. Unlike some internet docs that put out irresponsible suggestions without blinking an eye.

            1. Wow, Barb, calm down. And could you please logically point out where in my above comment I was being ridiculous, please? I fail to see any garbage.

              This was your statement: “I think we have to consider who is likely to be taking the fasting advice.. Dr Greger draws an enthusiastic crowd with all different health issues going on, from elite athletes to the very sick. And some have not seen their doctor in a long time. It’s only reasonable that he would take a conservative stance on fasting where there is an element of risk for those are walking around with untreated health issues who want to try fasting.”

              You literally concocted a theory that Dr. Greger’s stance is due to precaution over a particular audience, I merely pointed out that this was a totally concocted idea that does not go along with the reasoning behind his stance presented in the video–the evidence–and that it seemed to be an idea based off of nothing but your own rationalizing another’s stance to coincide more with your own as it appears, based on your comment, that you think he’s exaggerating the risk to some extent. If that was not what you meant by your statement, you could have easily explained so without getting defensive and creating a silly competition about who studies more…

    3. Many people have played Russian Roulette and survived too. That doesn’t prove Russian Roulette is safe for everyone.

      It’s not like Greger is just expressing a personal opinion here. He cites the evidence. What we do with it is up to us. He concludes that fasting for three days or more should be done under medical supervision. If you think that evidence and his conclusion isn’t relevant to you or your circumstances, though, fine..

  13. I do believe in a whole foods plant based diet and that is the kind of diet I eat for the most part. But this series does remind me that I lost a lot of weight by exercising everyday with some calorie control. But because I was exercising everyday and still to this day I was able to lose 95 and now 5 additional pounds and NEVER eat less than 2000 calories a day. I even found I was losing weight eating a little over 3000 calories a day. I do believe exercise is better than *dieting* which means a calorie cutting diet, and exercising regularly with moderate calorie intake is a whole lot better than a starvation diet to lose weight. Diet in the sense of good nutrition from whole plant foods is of paramount importance and this video reminds us that dieting and esp. extreme dieting can result in nutritional deficiencies. Daily regular exercising eliminates the need to go on any severe calorie restricted diet in order to lose weight. Of course plants are the best thing to eat, but cutting calories is not the way to go. I have kept all my weight off for over 9 years now, regularly eating a little over 3000 calories a day and have also switched to a plant based diet, which is not calorie restricted. I pretty much avoid meat, but find it difficult to totally avoid dairy as an ingredient in my foods, but have greatly cut down on dairy as an ingredient.

    1. Daniel Wagle,

      My experience any my husband’s support the adage: Get thin in the kitchen. Get fit in the gym.

      About 20 years ago, I was overweight and out of shape. So I started an exercise program, and a year later I was much more fit, but had lost no weight (though I didn’t gain any, either). So then I changed my eating habits, to practicing portion control and making healthier choices (eg, substituting fruits for sweets and baked goods, eating more veggies, cutting back on juice, avoiding “junk food,” etc) and I gradually lost 25 pounds over about 18 months. I never went back to my old ways of eating, so I kept the weight off. I also continued to exercise. Then, when I transitioned to plant based whole food eating — I had been a vegetarian, so I dropped the dairy products and eggs — I lost another 10 pounds without meaning to. My husband lost weight when he started eating my vegetarian cooking (as a widower, he was eating a lot of processed food), and then even more weight when we switched to PBWF eating — and he didn’t change his activity levels at any point.

      I think that both what you eat and how much are important to weight and overall health. And exercise is important to overall health and to maintaining a healthy weight. But the junk food companies want us all to believe that we could eat all the junk food we want — but “sensibly, moderately, as part of a healthy diet,” whatever that means — but lose weight with exercise alone. I think that they know very well that is not true. But if we don’t eat their products, they will go out of business. So they really don’t want us to eat their products moderately, but rather immoderately. I wonder if they’re investing in health clubs and fitness centers and gyms? And perhaps in weight loss programs, too? That way, they could have their cake and eat it too.

      1. My experience of trying to lose weight without much exercise is that at most I could lose only about 30 pounds. But also, for exercise to help, at least in my case, to lose weight, it has to be daily and at least an hour. Sporadic exercise is not that helpful. And, I still can’t eat ALL that I want if I want to lose weight, but regular exercise enables a person to lose weight without starvation diets like this series suggests. Exercise enables weight loss at a higher caloric intake level than a person would be able to lose weight without exercise.The way to lose weight by exercise is to increase one’s daily exercise, but don’t increase the calorie intake level. Counting calories is effective, but with exercise, it involves being careful about increasing one’s caloric intake. Without any exercise, a person would have to drastically cut the number of calories they consume. The National Weight Control Registry which I am a member states that the vast majority of persons who lost weight and keep it off exercised from the beginning of their weight loss journey and continued it throughout their maintenance period. Dieting without exercise results in muscle loss and is a less healthy way to lose weight.

      2. What I do for exercise is to ride my bike everywhere, such as to work or to the store. I ride it everyday. It is a main source of transportation. I think that riding my bike as well as not eating meat is very helpful for the environment. Bicycling as a way of life did help me to lose a lot of weight. A lot of people might not lose weight by exercise because they are doing something they hate, like a treadmill, which of course is boring. Bicycling is very enjoyable and something I can enjoy doing for a long enough time to make a difference with my weight. But I never said exercise should be an excuse to eat junk food, but rather a way to eat more healthy food as well as more higher calories healthy foods, such as nuts. I eat nuts everyday as well as Greens. Eating plants, daily exercise and counting the quantity of calories is a winning combination for losing weight. Even with exercise, a person still has to pay attention to their diet, it just is that a person doesn’t have to cut back as much if they exercise a lot to lose weight. Certainly regular exercise spares a person from having to go on a starvation or very low calorie diet in order to lose weight.

  14. (Male) I did fasting thinking I would become Superman. What I got from it is muscle loss(can’t lift more than 25 lbs but weighting 130 lbs can explain it) and trouble sleeping. People spreading false information online have caused untold amounts of damage.

      1. Yes, aren’t we though. :-)

        As part of my morning exercise regimen (along with yoga exercises, rebounding, pushups, etc.), I also lift my trusty 8-lb dumbbells. One morning it will be the left arm, the next morning the right. Not more than a dozen times though. I figure that’s enough.

        1. “As part of my morning exercise regimen”
          – – – – – –

          Needless to say, BEFORE my hearty and delicious breakfast. During the 14-hour fasting window.

    1. Adrian,

      The internet is so loaded with false information and half-truths.

      I know that you are right that people are genuinely getting injured by it.

    2. “People spreading false information online have caused untold amounts of damage.”

      Yep…

      Now there are people vaping B12…. Um, where is there evidence that you can supplement via inhalation?

      Why don’t people ASK FOR THE EVIDENCE! Everyone just assumes if someone’s saying it or selling it, then they know what they’re talking about and it must be true. Then THEY start telling people the misinformation they’ve gathered and so on.

  15. It’s a dead giveaway that long term fasting (greater than 24hrs) is unhealthy when the medical studies gather information from autopsies…

  16. That explains it. If a patient gets pneumonia, colic or similar where they can’t eat for a while bad things can happen to them. Do hospitals IV patients with minerals and vitamins during that time? I don’t think they do because it could make things worse. So the infection may not kill but it can cause other damage.

    1. YT found something for me about this topic. It’s about intravenous vitamin C for people with sepsis. Here’s the link. https://youtu.be/HXs5Xzr6qCI. The VICTAS trial offers some hope and you can keep an eye on it. Here’s the citation.

      Hager, D.N., Hooper, M.H., Bernard, G.R. et al. The Vitamin C, Thiamine and Steroids in Sepsis (VICTAS) Protocol: a prospective, multi-center, double-blind, adaptive sample size, randomized, placebo-controlled, clinical trial. Trials 20, 197 (2019) doi:10.1186/s13063-019-3254-2

    2. This video from EONutrition really explains the functional B-1 deficiency diabetics get. It’s called ‘Vitamin B1 (Thiamine) Deficiency, Insulin Resistance & Diabetes’. The take away is that diabetics waste thiamine in the urine and have a higher requirement. Here’s the link: https://youtu.be/m3DopqTz1Q4. So diabetics should be supplementing b1 and it should be the standard of care. Hopefully doctors start doing it.

    3. I just watched the London Real video and the snippet about normal pressure hydrocephalus. If only I had known about it. That’s probably what my Dad had because I noticed brief moments of him where he said intelligent things that someone with dementia wouldn’t be able to if only for a moment. I’m wrong but I’ll just write it anyway; B1 functional deficiency leading to fluid retention and so the risk of normal pressure hydrocephalus goes up.

        1. With all the health brochures I received, I never came across this information. It should be explained that there are types of dementia. My GP just told me to prepare and when I asked he said there’s nothing to be done. Why do doctors just take away all your hope like that? I didn’t even look into it and press for more options.

  17. Please Dr Greger, my wife and I are in the Wellness lifestyle. What about Intermittent Fasting please? We have wonderful successes with not eating from 20:00 to roughly noon the next day. Maintenance of an ideal weight and plenty of energy amongst other achievements….

    1. I believe he’ll be addressing intermittent fasting in an upcoming video. He’s stated he’s going to have a lot of fasting videos coming out. I’m glad the slew of them started!

  18. I think my health issues of today was caused by fasting. I did a 16 day water fast and a few days re-feed 12 years ago and it looks from that time my healthwent down hill.

    Now i feel tired al the time, get painfull muscle cramps when i contract my hamstrings,toes and fingers.

    Sofar blood test shows nothing. i feel more and more that long fast was a mistake.

    Any had similar experiences

  19. Despite, or maybe because of a lifetime of alternating caloric restriction, I could not budge the scale unless I got under 1200-1300 calories a day, and even on an SOS free WFPB diet (well, not truly salt free) I am still “remarkably efficient” at holding onto some excess lbs. Though I lost around 150 lbs 8 or so years ago… before going WFPB I was (obviously) morbidly obese and had a slew of chronic health issues including RA, which has improved dramatically, but I will still get occasional flares. Aside from taking potent drugs with tons of horrific side effects, 5-7 days of water fasting is the thing which will halt it in it’s tracks, and for me also has the great fringe benefit of knocking off some lbs. Despite what was said, it has also been the most permanent way ever for me to keep those pounds off. I know I’m an exception to the norm, but fasting has been a small miracle for me. I couldn’t afford going off to a center for medical monitoring, and no one around here has a clue, but I had to do something, so poured myself into research. The healing success of fasting, especially from the records of True North, coupled with the knowledge that we developed the ability to fast, unlike the other primates, for a reason…enhancing survival…initially spurred me on. I started with a 24 hour fast, and each successive attempt got a bit longer until I worked up to a week. It certainly isn’t fun, and I wouldn’t do it if it weren’t so effective, but it is still a FAR better and more effective option than anything my doctors ever offered! Caution is always prudent of course, but I don’t want people who can benefit as much as I have to just automatically dismiss it as too risky. I realize this video is about fasting for weight loss, but it sure works for me there too! YMMV

    1. Vegetater,

      Thanks for sharing.

      There are health issues which would be the one thing which I would consider doing it for, such as cancer.

      Still waiting to hear what is happening with my father, but I did get my brother to do a 48-hour water fast when he was diagnosed and that was all he could do, but the goal was any improvement at all in his immune system and any heightening of his immune system recognizing cancer as cancer. He is doing immunotherapy right now. Possibly. It is double-blind, but he has some of the symptoms as if he is on immunotherapy. Placebo-symptoms? Maybe.

    2. Vegetater – thanks for your thoughts and comments. I, too, benefit from fasting when needed and I find it helpful. I rather enjoy the feeling of feeling a bit hungry. I’ve learned to make friends with the rumbling gut. When I get through the acute feeling of hunger I find I enjoy the lightness I feel in my abdomen and the energy that kicks in.

    3. Vegetator, I have to say that going by the evidence shown in this video, it hardly seems that humans developed any ability to fast when there are such detrimental and life-threatening consequences of fasting without proper supplementation. If you need to be supplemented for something in order to survive or avoid serious risk, it does not seem to be a part of our natural evolution.

      One reason you may have a problem keeping lbs off could (in theory) be due to restriction and fasting based on possible consequences to our gut microbiome: http://sitn.hms.harvard.edu/flash/2018/eating-for-a-trillion/ I’m not sure (obviously), but it’s something I’m really wondering about.

  20. So glad the fasting videos are out! This information is so vital, people are so quick to go to extremes based off of hype rather than evidence and look how dangerous it is. I actually know someone who did a long-term fast and went into a coma, had to have a shot in their spine, and had amnesia upon coming out of their coma and is still an advocate for fasting. They do say they didn’t do it right so hopefully they mean under supervision and with supplementation.

    So to me, this is evidence enough to see that WE ARE MEANT TO EAT FOOD, it’s why we do it and fasting is just that, starvation. What miraculous, spectacular outcome could justify doing something that OBVIOUSLY messes with your body in such potentially (as in if not medically supervised and properly supplemented) disastrous ways? Why would you know all this and be like “oh, I think I’m going to ‘cleanse’ myself with a fast!” Um, no thanks, I like my heart muscles, lean body mass, etc.. etc…

    But here’s something I’m very curious about and hope that it’s focused in one of your upcoming videos… What the hell happens to our precious gut flora when doing a prolonged fast? It would literally become starved and die off, so what kind of consequences does that produce in the short and perhaps especially long term? It’s not as though any administered multi vitamin would supply fiber to keep our gut bacteria alive.

    1. S,

      Thanks for sharing.

      Honestly, when my pastor went into his stupor or whatever it was at the end of a 3-day water fast, it definitely got my attention. It looked like he had died with his eyes open. Not sure how long he had been like that before people noticed because it was a worship service, but he was totally unresponsive and he wasn’t moving or looking at anybody. He really looked like a statue. I think it was 15-minutes before the ambulance took him away, but again I don’t know if it had been a half-hour like that or even longer. It was scary.

        1. S,

          Yeah, I thought about that.

          It is hard to believe that being low in electrolytes after so few days of fasting would cause that type of reaction.

          The pastor story in the video might be why even global ministries started asking people health questions before strokes.

          They switched from pre-9/11 and the year after it from being fasting oriented – maybe for 3 years.

          I remember being at a fasting and prayer solemn assembly in Boston the week after 9/11 and there was a bomb threat against us praying but nobody left.

          New York prayer gathering was after that and it was so hot that my friend got sun stroke and vomited half the prayer meeting even with the fasting.

          That must have been August.

          I had a few friends who were in the city feeding the workers. Some had watched the plane crash into the building and were able to bring food to the workers that day. One of my friends who had lost her job moved down there to feed and pray for the people cleaning up.

          There were still a lot of fasting and prayer meetings after that but those ones are ones I remember.

          I had gone to David Wilkerson’s church the week before 9/11. They had felt like God showed them that something big was going to happen and they canceled every non-necessary thing and were just doing repentance and confession of sins services and were crying out for mercy for weeks before 9/11.

          I remember that my friend wanted to go to the Twin Towers that weekend before and I said that I was too wiped out from the meetings.

          I inwardly was thinking that I could be a tourist next time, but that was Labor Day weekend and those buildings were gone.

    1. To me, the fact that people who skip meals get worse with strokes and heart attacks makes me wonder what the mechanism is.

      Intermittent fasting is supposed to lower the risk of stroke, but skipping breakfast raises it markedly.

      Is it the type of food you eat when you skip breakfast helps stroke, but if you skip dinner or just don’t eat after dinner, you get your blood sugar under control?

      Either way, when I tried to look it up, I found this about extended fasting increasing the risk of rare strokes, so I guess this link is on topic.

      https://www.aan.com/PressRoom/home/PressRelease/589

          1. So in the elderly

            Blood pressure drops after breakfast

            (which is nearest the time when ischemic strokes happen)

            Blood pressure stays elevated after a late dinner and doesn’t drop for bedtime.

              1. Water before bed lowers stroke risk

                https://academic.oup.com/aje/article/155/9/827/58224

                Water before breakfast is used when people have too low of blood pressure to prevent it from dropping lower. That will be something I tell my uncle whose blood pressure is low.

                But does drinking water in the morning before breakfast undo the benefit of breakfast lowering BP enough to lower strokes?

                Forgive me, I am a Little Dipper and not a skinny Little Dipper. Possibly a non-dipper, except that I don’t fall asleep so maybe sometimes I am a Big Dipper.

                Should I be drinking water or eating breakfast at 4 30 in the morning when I can’t sleep?

                1. Water raises blood pressure…. the mystery continues… because another one was water nomalizes blood pressure, but water might be another white coat contributor.

                  On the average, 16 ounces of tap water raised blood pressure about 40 millimeters of mercury in patients with autonomic failure. Blood pressure started increasing within two or three minutes after the water was ingested, increased rapidly over the next 15 minutes, and then began to decrease after about 60 minutes. Drinking more water at 60 minutes caused the blood pressure effect to be sustained for another hour.

                  In older normal subjects, the average increase in blood pressure was 11 millimeters of mercury.

                  There is something about the water itself that causes the increase in blood pressure; intravenous infusion of 16 ounces of sugar solution did not elicit the effect. In addition, the effect is “dose-dependent” — the higher the water intake, the larger the increase in blood pressure.

                  “We do not know how water raises blood pressure, but it is the solute-free water itself, whether warm, room temperature, or cold that elicits the effect,” said Dr. Jens Jordan, a former postdoctoral fellow in Clinical Pharmacology and lead author of the study.

                    1. I wonder if the phytoestrogens go up and down with soy and with HRT.

                      They said that there were a few studies where the risk seemed to go down with HRT, but most the risk went up.

                      For healthy postmenopausal women, standard dose hormone therapy increases stroke risk by about a third

                      It seems like morning and evening might be a real factor? Aldosterone or Renin or some other thing that I don’t understand yet?

                    2. I looked up Homocysteine and the shift workers’ graph was interesting, but I was confused because Homocysteine is the lowest in the morning and yet it is considered a risk factor for stroke, but it is the lowest when more people get strokes?

                      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC520826/

                      I am going to hypothesize that it isn’t the direct link to a stroke. It might prepare the endothelials to fail when the blood pressure rises in the morning, but what causes the blood pressure to rise. It isn’t homocysteine. Are we back to the fact that I don’t know the hormones yet?

                    3. Cortisol raises the blood pressure in the morning and it causes damage to the endothelials. Inhibiting it gets rid of the endothelial damage related to mental stress.

                      There is an article called: Inhibition of Cortisol Production With Metyrapone Prevents Mental Stress-Induced Endothelial Dysfunction and Baroreflex Impairment

                      Cortisol enhances sensitivity of tissues of blood vessels and heart to noradrenaline, vasopressin and angiotensin II, resulting in increased blood pressure. In addition, it affects the water and electrolyte balance, increasing retention of water and sodium [3, 7, 9].

                      Cortisol causes you to keep your electrolytes is one of those odd facts that makes me think having a stressful time during your water fast might not be such a bad thing.

                  1. I wonder how many times water itself might be responsible for the placebo effect?

                    They take the placebo with water and the water raises or lowers the blood pressure and thins the blood and changes the sodium levels and hydrates the kidneys, affects the hormones, etc.

  21. Just read this interesting research:

    …Such histone marks are broadly known as “epigenetic” marks because they effectively help control, or program, which genes are turned on and which are turned off in a cell.

    The precise functions of crotonyl marks have been somewhat mysterious. But Strahl and Morrison’s labs found evidence that these marks occur naturally under low-nutrient conditions when the main form of chemical energy in cells, related to glucose, is less available and cells start to scavenge chemical energy from fat-related molecules. Fatty acids are generated as byproducts of this alternate energy production process and soon make their way to the nucleus. There enzymes start attaching one form of these fatty acids, crotonyls, to histones. That forces a change in gene activity that slows growth and otherwise adapts the cell for low-nutrient conditions.

    Crotonylation in this context appears to have nearly the opposite function of a better-known histone marking called acetylation, which uses byproducts of normal, glucose-related energy production to keep growth genes switched on.

    Strahl and Morrison made these findings by studying yeast, which have a natural tendency to cycle cleanly between nutrient-rich and nutrient-poor states. This made it easier to isolate the function of histone crotonylation. The scientists now plan to study the role of this type of epigenetic mark in humans, where it is prominent in gut and brain cells, and its function often appears to be disrupted in cancers.

    “We think this area of research could give us some key insights into how cancer cells are able to survive,” Strahl said.

    https://www.eurekalert.org/pub_releases/2019-11/uonc-fof110519.php

    I personally found the following remarks interesting as they relate to fasting: …under low-nutrient conditions when the main form of chemical energy in cells, related to glucose, is less available and cells start to scavenge chemical energy from fat-related molecules.

  22. Here is information on the benefits of fasting for reducing cellular aging. This is research done by Japanese cell biologist Yoshinori Ohsumi who won the 2016 Nobel Prize in physiology for his work on fasting.
    https://www.bluezones.com/2018/10/fasting-for-health-and-longevity-nobel-prize-winning-research-on-cell-aging/

    Valter Longo, Ph.D., director of the Longevity Institute at U of California – Davis and professor at same in the Biology and Gerontology department has also studied the physiology of fasting for 30 years. Longo has developed a way to fast the body but also give the body nutrients at the same time so that one gets the benefits of fasting without hardship on the body. You can get this information from his recent book “The Longevity Diet” which outlines how to do this safely and with minimal discomfort.

    I have fasted numbers of times and have had a perfectly good experience with it. People also fast – naturally – when they are ill and do not want to eat. It’s a natural biological process necessary for healing when one is ill. Ghandi fasted for 71 days. One can also learn more about fasting at True North clinic in California. Here is their site: https://www.healthpromoting.com/

    When one thinks about the role of food in our society and sees how much disease we have from our chronically overfed state (Type II diabetes for one), fasting upon occasion might be a good thing. No one is going to drop dead from missing a few meals here and there. One should be educated about fasting. Likewise one doesn’t need to fear it either.

  23. Ruth, thanks for the Blue Zones link. The topic of autophagy is fascinating! I have watched many of Dr Longo’s lectures and interviews and was interested to hear he himself eats twice per day. Over the summer, circumstance led me to do the same a number of times, as well as quitting snacking. It was a positive experience and one that I think I will adopt permanently. I prefer to have a ‘lighter’ feel as opposed to feeling full all the time. My weight more easily stays in line, and I am putting on more muscle. (my late lunches come after workouts so this might have some bearing on it).
    I recently went through extensive medical investigations and at the end of it my doctor said “keep doing what you’re doing!” … so I will lol.

  24. Speaking of gut microbiome (in an earlier comment of mine), I’ve read how our gut microbiome can boost our metabolism before but here is a really interesting article from Harvard explaining how have healthy gut microbiome may actually be a key to weight loss with lasting results: http://sitn.hms.harvard.edu/flash/2018/eating-for-a-trillion/

    Which begs the question further, what does fasting do to your gut microbiome; what kind of consequences occur from starving our micriobiome including in regards to weight loss? So could fasting actually be counterproductive to lasting weight loss in this regard? That is to say, if we starve our microbiome to death or drastically deplete the diversity and population, how might that affect our metabolism in the short and long term? Some people go on long-term fasts once a year at clinics.

    The above linked article has some interesting things to say about the paleo diet and the keto diet as well. I recommend checking it out. There is so much about our microbiome still being discovered, I always look forward to learning more and more about it.

  25. It’s one thing to report glibly on water fasting “dangers” based on the studies and another entirely to know something about the topic. I would suggest that professionals who specialize might be in the later group.
    https://www.youtube.com/watch?v=5L-6P9kjuWs&feature=youtu.be

    Sick people die, no kidding, often when they are grasping at straws.
    People who have adopted a wellness model like the Natural Hygienists, self fast with out problem as a basic tenet of health. Those who believe that the only facts worth considering are research articles are lit searchers not clinicians. Not to rain unfavorably on published studies but at this juncture in history it is most definitely a game of Science for Sale.

        1. I’ll let anyone wasting their time reading your comments decide for themselves where the stupidity lies.

          “Medical experts consider natural hygiene practices such as anti-vaccination , fasting and food combining to be quackery .[1] [26] [27] There is no scientific evidence that prolonged fasting provides any significant health benefits.[26] [28] [29] A prolonged fast may cause “anemia, impairment of liver function, kidney stones, postural hypotension, mineral imbalances, and other undesirable side effects.”[29]

          Claims from natural hygienists about fasting curing cancer are not supported by scientific evidence. According to the American Cancer Society , “available scientific evidence does not support claims that fasting is effective for preventing or treating cancer in humans.”[30] “

        2. It was a matter of convenience. I could have wasted more valuable time making the same point with less controversial sources no doubt, but why time on a group of anti-scientific, anti-vaxer food combiners.

        1. There are times when people are clearly morons; clearly being idiots and aggressively and relentlessly so. In these times, it’s justifiable or at the VERY least, extremely understandable when people blatantly just say it… “you’re an idiot” or mention the glaring elephant in the room “stupidity.” Apart from those times, calling people stupid, morons, idiots, etc. just makes you look the part. Certainly gengo is far the realm of stupidity, I’ve seen their comments, NOT that your comment needs or deserves a rebuttal, just saying in any case.

          1. S, you seem to specialize in getting things exactly wrong. Your sentences need editing and real help for content and context. Though you did get one thing correct, the comment did not beg rebuttal.

    1. “Sick people die, no kidding”

      What a disgusting way of blaming the people seeking help. Just the kind of shameless copout argument made by all kinds in the holistic field who end up harming their patients.

      You’re literally taking the stance that we should trust the self-proclaimed knowers rather than the evidence… Are you in like some kind of field of fasting or something? Or maybe just a die hard believer. In any case, you’re preaching nonsense by suggesting people don’t go by evidence.

      There’s other horror stories out there of people getting sick and almost dying (and not getting a refund unless signing to not share their story) by following unqualified supervisors and unqualified clinics. Fasting is starvation and a lot happens to the body when it’s starved.

      1. I am not “in the field” just have 30 years of clinical experience and discernment
        and no I am not literally taking the stance you suggest or a die hard believer, and no
        I am not preaching. What you believe qualifies is highly suspect. Your opinion of starvation equivalence is
        testimony to your knowledge about health approaching zero…

        1. No, Paul, my statement of comparing fasting to starvation is testimony to the fact that not eating is depriving your body of food and while this might be an answer to cancer patients or benefit people who are doing it safely and properly as suggested in video, the act of depriving yourself of something vital to survival would, naturally, be risky. There are some fasting advocates who even suggest no water during fasts… then you have bretharian believers, INSANELY enough, so yeah, EVIDENCE is pretty essential. You just disagree with the existing data so you’re upset at its presentation.

          1. No S, fasting is not equivalent to deprivation. It is resting the body and facilitating the elimination of toxins as quickly as possible. Advocates are not experts and I have never heard of the suggestion to eliminate water in over 30 years. It is really disingenuous to equate fasting with breatharians and serves no rational purpose at all. I never disagreed with “data” just took issue with what expertise is and is not…

            1. “fasting is not equivalent to deprivation”

              DEFINITIVELY it is. The question is are there benefits for those doing it under qualified care such as True North along with the question of what harm might it cause even under qualified care. My first red flag is our microbiome.

              I assure you I did not equate fasting with breatharians, I absolutely would not do so. My only point was that because there is so much hype and even insanity out there, evidence is extremely important.

              1. And I would add to my statement of fasting being deprivation by definition, that while it is in fact the act of depriving oneself of food, I realize not all who fast feel deprived and as reported often feel the opposite.

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