14 ms·

I really urge people to do a multi-day fast a few times a year. I wrote a little guide about it that I shared previously [1]. You can wonder about these longte

by theNJR 5y ago

I really urge people to do a multi-day fast a few times a year. I wrote a little guide about it that I shared previously [1]. You can wonder about these longterm positive effects, but it's sort of a Pascals wager. You lose absolutely nothing and it could have significant upside. Worst case, it makes you confront your relationship to food and offers a great mental challenge. One cool thing that you learn is that there is a maximum hungry you get. It doesn't ever go past that point (and you've felt it before without fasting). Even better, it ebbs and flows. You won't be in a state of "OMG I am starving!!" all day long. It hits at normal eating times, and then retreats to the background. Anyway, just try it. [1]https://www.nicholasjrobinson.com/blog/general/five-day-fasting-guide-freedom-from-food-people-and-technology https://www.nicholasjrobinson.com/blog/general/five-day-fast...

solarmist 5y ago
The more studies pile up, the less it seems to matter the length of a given fast, but more the total time spent in a fasting state relative to a fed state. So as a taster, you can do multiple 24-hour fasts and get the same experience from a health point of view (everything else is different, though). That said, at some point, I’m interested in trying a multiple-day fast myself but haven’t taken the plunge yet.
- tejohnso 5y ago
  > The more studies pile up, the less it seems to matter the length of a given fast, but more the total time spent in a fasting state relative to a fed state. Yes, I've noticed this as well. Personally I fast for 17 hours every day and I've noticed I feel the benefits without negative consequences. Once in a while I'll go for a 3 day fast but aside from the personal challenge accomplishment I don't notice a major gain. My experience is all very non scientific. For the more rigorous science, I usually look to Peter Attia[1] [1]: https://peterattiamd.com/ https://peterattiamd.com/
- srik 5y ago
  > you can do multiple 24-hour fasts and get the same experience from a health point of view NO, that's incorrect. The length matters a lot. In fact, a major change occurs after the 2-3 day mark, when body glycogen stores are depleted and your body shifts to ketosis etc. Another major marker has to do with when a much coveted state called autophagy is activated.
  - solarmist 5y ago
    I have not heard this. Can you share more? I’m familiar with ketosis but unfamiliar with it in conjunction with fasting. Or benefits for otherwise healthy people. Ketosis has lots of downsides for normally healthy people. Ketosis is literally the start of starvation, so I'm dubious of widespread health benefits. I know it is extremely beneficial to people with a history of seizures, but that's it.
    - brigandish 5y ago
      > Ketosis has lots of downsides for normally healthy people. I've been considering trying ketosis but all I've heard are good things, what are the downsides?
      - solarmist 5y ago
        The most significant downsides are psychological and kidney stones, plus its literally (by definition) your body’s signal of starvation. https://en.wikipedia.org/wiki/Ketosis#Safety https://en.wikipedia.org/wiki/Ketosis#Safety Oh and this gem from the article on starvation. > After two or three days of fasting, the liver begins to synthesize ketone bodies from precursors obtained from fatty acid breakdown. The brain uses these ketone bodies as fuel, thus cutting its requirement for glucose. After fasting for three days, the brain gets 30% of its energy from ketone bodies. After four days, this may increase to 70% or more.[11] Thus, the production of ketone bodies cuts the brain's glucose requirement from 80 g per day to 30 g per day, about 35% of normal, with 65% derived from ketone bodies. But of the brain's remaining 30 g requirement, 20 g per day can be produced by the liver from glycerol (itself a product of fat breakdown). This still leaves a deficit of about 10 g of glucose per day that must be supplied from another source; this other source will be the body's own proteins. This is the biggest reason I've never done more than toy with ketosis is the body consuming muscle for protein to supply that remaining 10g of glucose per day. Esp. because 1 lb of muscle only 1,800 Cal vs 3,500 Cal / lb. Fat.
anonu 5y ago
I find that physically you are fine when you do this: you can walk around, do house work, etc... but mentally you are shot. I would love to try this - but certainly dont have 5 consecutive days where I can be a mental vegetable. The brain needs constant fuel. Anyone experience this as well?
- pmulard 5y ago
  I found my experience to be the opposite. I had clear mental focus, but felt physically drained of energy the entire time. I did a 3.5 day water fast, with the majority of my fluids from water/tea with salt for electrolytes. My sleep was pretty terrible up until the last night, when I got a solid 8 hours without waking up once. I usually wake up 8-10 times a night, so this was a huge breakthrough. I also regained my energy on that last half day and felt incredible. What type of fasting did you do, and what liquids did you drink?
- arcticbull 5y ago
  I generally find myself sharper, more alert and with much more energy. This continues the longer your fast lasts, up until day 7ish in my case. Your noradrenaline levels spike when fasting, and it can make it hard to sleep - too juiced haha. If you're finding yourself tired, it could be a lack of electrolytes. Try a teaspoon of salt in a pint of water. I tend to drink coffee when water fasting, which has an outsize effect.
  - andai 5y ago
    Same. It makes sense to me intuitively: when you're hungry, you go into an alert "hunting mode". My sense of smell is normally very weak, but when I am hungry it increases by a factor of 100.
- mcculley 5y ago
  (Consider using “I” instead of “you”.) I have found that once I become fat adapted, I no longer suffer from mental clarity problems. It takes a couple of days without carbs to get there for me.
- 5y ago
onlyrealcuzzo 5y ago
Wait. Why is it possible fasting has upsides, but it is not possible it has downsides?
- arcticbull 5y ago
  You could ask the same question about eating 3-4 meals per day. This is a relatively new phenomenon for humans - starting in the 1700s. Feast/famine is how we used to live. The Romans ate one meal a day and frowned upon breakfast, for instance - their default was what we would now consider OMAD fasting. [1] [1] https://www.bbc.com/news/magazine-20243692 https://www.bbc.com/news/magazine-20243692
  - throwawaymanbot 5y ago
    what was their life expectancy?
  - onlyrealcuzzo 5y ago
    Just because you can ask the same question about eating 3-4 meals per day DOES NOT mean that we can automatically assume that fasting might be better but is definitely not worse. It could be better, worse, or the same. We don't know. And there's no reason to assume that it might be better while it is definitely not worse (and therefore an obvious choice).
    - arcticbull 5y ago
      There are reasons to assume it might be better. It dramatically raises HGH levels [1] which improves body composition (increases the proportion of muscle to fat), improves insulin sensitivity, lowers blood pressure and reduces general inflammation / oxidative stress - even in the absence of weight loss [2]. It also burns fat (obviously, since there's nothing better to burn when fasting) which for the vast majority of folks is strictly better than the alternative. There's a lot of compelling studies being done at the moment, including the interaction of fasting with the immune system. [3] > Last week, in a paper just published in the New England Journal of Medicine [4], Rafael de Cabo and Mark Mattson reviewed multiple strategies for fasting that have been tested in the years since Longo's study. The news continues to be very encouraging: intermittent fasting is good for you. I'm not saying it's conclusive but to suggest there's no reason to think it might be better is disingenuous. There's been some pretty interesting studies over the last few decades (few and far between, but interesting) - and the idea of fasting for heath is enjoying something of a renaissance in nutrition research these days. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC329619/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC329619/ [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5990470/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5990470/ [3] https://www.forbes.com/sites/stevensalzberg/2020/01/06/can-intermittent-fasting-reset-your-immune-system/?sh=75ff77527ac2 https://www.forbes.com/sites/stevensalzberg/2020/01/06/can-i... [4] https://www.nejm.org/doi/10.1056/NEJMra1905136 https://www.nejm.org/doi/10.1056/NEJMra1905136
Graziano_M 5y ago
I used to do 16/8 or 18/6 and it's pretty easy. I still usually don't eat breakfast because it makes it easy to get > 12 hours fasted. A few months ago, though, I started doing a 24 hour fast every week. It takes some planning but it's surprisingly easy. I'm damn hungry by the end, but it's never been an issue. I'll even work out and lift heavy 22+ hours into the fast without a noticeable decline in strength. I have no plan to stop doing this.
- solarmist 5y ago
  I'm curious what planning you mean? I do it without planning and haven't had an issue.
  - Graziano_M 5y ago
    Planning my social life around it. I'm not as fun at dinner if all I can have is water.
Gregam3 5y ago
I love fasting and typically I have one meal and fast for 22 hours a day, but please be careful with multi day fasting. I drink a lot of water and on two occasions on 60 hour fasts I passed out cold, falling to the ground and chipping one of my front teeth in the process, but it could have ended much worse. I eventually figured out I was not consuming enough electrolytes relative to my water consumption, I still recommend long term fasts but please do more research than I did and be careful. I have kept that chip in my tooth to this day to remind me my naivety and how lucky I was.
gcheong 5y ago
The study in the OP is specific to alternate day fasting though, which is generally much more tolerable than straight-up multi-day fasts, and can be done over a much longer term.
vagab0nd 5y ago
How do you overcome upset stomach? If I don't eat for half a day my stomach starts to hurt.

by theNJR 5y ago

solarmist 5y ago

The more studies pile up, the less it seems to matter the length of a given fast, but more the total time spent in a fasting state relative to a fed state. So as a taster, you can do multiple 24-hour fasts and get the same experience from a health point of view (everything else is different, though). That said, at some point, I’m interested in trying a multiple-day fast myself but haven’t taken the plunge yet.

tejohnso 5y ago
> The more studies pile up, the less it seems to matter the length of a given fast, but more the total time spent in a fasting state relative to a fed state. Yes, I've noticed this as well. Personally I fast for 17 hours every day and I've noticed I feel the benefits without negative consequences. Once in a while I'll go for a 3 day fast but aside from the personal challenge accomplishment I don't notice a major gain. My experience is all very non scientific. For the more rigorous science, I usually look to Peter Attia[1] [1]: https://peterattiamd.com/ https://peterattiamd.com/
srik 5y ago
> you can do multiple 24-hour fasts and get the same experience from a health point of view NO, that's incorrect. The length matters a lot. In fact, a major change occurs after the 2-3 day mark, when body glycogen stores are depleted and your body shifts to ketosis etc. Another major marker has to do with when a much coveted state called autophagy is activated.
- solarmist 5y ago
  I have not heard this. Can you share more? I’m familiar with ketosis but unfamiliar with it in conjunction with fasting. Or benefits for otherwise healthy people. Ketosis has lots of downsides for normally healthy people. Ketosis is literally the start of starvation, so I'm dubious of widespread health benefits. I know it is extremely beneficial to people with a history of seizures, but that's it.
  - brigandish 5y ago
    > Ketosis has lots of downsides for normally healthy people. I've been considering trying ketosis but all I've heard are good things, what are the downsides?
    - solarmist 5y ago
      The most significant downsides are psychological and kidney stones, plus its literally (by definition) your body’s signal of starvation. https://en.wikipedia.org/wiki/Ketosis#Safety https://en.wikipedia.org/wiki/Ketosis#Safety Oh and this gem from the article on starvation. > After two or three days of fasting, the liver begins to synthesize ketone bodies from precursors obtained from fatty acid breakdown. The brain uses these ketone bodies as fuel, thus cutting its requirement for glucose. After fasting for three days, the brain gets 30% of its energy from ketone bodies. After four days, this may increase to 70% or more.[11] Thus, the production of ketone bodies cuts the brain's glucose requirement from 80 g per day to 30 g per day, about 35% of normal, with 65% derived from ketone bodies. But of the brain's remaining 30 g requirement, 20 g per day can be produced by the liver from glycerol (itself a product of fat breakdown). This still leaves a deficit of about 10 g of glucose per day that must be supplied from another source; this other source will be the body's own proteins. This is the biggest reason I've never done more than toy with ketosis is the body consuming muscle for protein to supply that remaining 10g of glucose per day. Esp. because 1 lb of muscle only 1,800 Cal vs 3,500 Cal / lb. Fat.

anonu 5y ago

I find that physically you are fine when you do this: you can walk around, do house work, etc... but mentally you are shot. I would love to try this - but certainly dont have 5 consecutive days where I can be a mental vegetable. The brain needs constant fuel. Anyone experience this as well?

pmulard 5y ago
I found my experience to be the opposite. I had clear mental focus, but felt physically drained of energy the entire time. I did a 3.5 day water fast, with the majority of my fluids from water/tea with salt for electrolytes. My sleep was pretty terrible up until the last night, when I got a solid 8 hours without waking up once. I usually wake up 8-10 times a night, so this was a huge breakthrough. I also regained my energy on that last half day and felt incredible. What type of fasting did you do, and what liquids did you drink?
arcticbull 5y ago
I generally find myself sharper, more alert and with much more energy. This continues the longer your fast lasts, up until day 7ish in my case. Your noradrenaline levels spike when fasting, and it can make it hard to sleep - too juiced haha. If you're finding yourself tired, it could be a lack of electrolytes. Try a teaspoon of salt in a pint of water. I tend to drink coffee when water fasting, which has an outsize effect.
- andai 5y ago
  Same. It makes sense to me intuitively: when you're hungry, you go into an alert "hunting mode". My sense of smell is normally very weak, but when I am hungry it increases by a factor of 100.
mcculley 5y ago
(Consider using “I” instead of “you”.) I have found that once I become fat adapted, I no longer suffer from mental clarity problems. It takes a couple of days without carbs to get there for me.
5y ago

onlyrealcuzzo 5y ago

Wait. Why is it possible fasting has upsides, but it is not possible it has downsides?

arcticbull 5y ago
You could ask the same question about eating 3-4 meals per day. This is a relatively new phenomenon for humans - starting in the 1700s. Feast/famine is how we used to live. The Romans ate one meal a day and frowned upon breakfast, for instance - their default was what we would now consider OMAD fasting. [1] [1] https://www.bbc.com/news/magazine-20243692 https://www.bbc.com/news/magazine-20243692
- throwawaymanbot 5y ago
  what was their life expectancy?
- onlyrealcuzzo 5y ago
  Just because you can ask the same question about eating 3-4 meals per day DOES NOT mean that we can automatically assume that fasting might be better but is definitely not worse. It could be better, worse, or the same. We don't know. And there's no reason to assume that it might be better while it is definitely not worse (and therefore an obvious choice).
  - arcticbull 5y ago
    There are reasons to assume it might be better. It dramatically raises HGH levels [1] which improves body composition (increases the proportion of muscle to fat), improves insulin sensitivity, lowers blood pressure and reduces general inflammation / oxidative stress - even in the absence of weight loss [2]. It also burns fat (obviously, since there's nothing better to burn when fasting) which for the vast majority of folks is strictly better than the alternative. There's a lot of compelling studies being done at the moment, including the interaction of fasting with the immune system. [3] > Last week, in a paper just published in the New England Journal of Medicine [4], Rafael de Cabo and Mark Mattson reviewed multiple strategies for fasting that have been tested in the years since Longo's study. The news continues to be very encouraging: intermittent fasting is good for you. I'm not saying it's conclusive but to suggest there's no reason to think it might be better is disingenuous. There's been some pretty interesting studies over the last few decades (few and far between, but interesting) - and the idea of fasting for heath is enjoying something of a renaissance in nutrition research these days. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC329619/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC329619/ [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5990470/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5990470/ [3] https://www.forbes.com/sites/stevensalzberg/2020/01/06/can-intermittent-fasting-reset-your-immune-system/?sh=75ff77527ac2 https://www.forbes.com/sites/stevensalzberg/2020/01/06/can-i... [4] https://www.nejm.org/doi/10.1056/NEJMra1905136 https://www.nejm.org/doi/10.1056/NEJMra1905136

Graziano_M 5y ago

I used to do 16/8 or 18/6 and it's pretty easy. I still usually don't eat breakfast because it makes it easy to get > 12 hours fasted. A few months ago, though, I started doing a 24 hour fast every week. It takes some planning but it's surprisingly easy. I'm damn hungry by the end, but it's never been an issue. I'll even work out and lift heavy 22+ hours into the fast without a noticeable decline in strength. I have no plan to stop doing this.

solarmist 5y ago
I'm curious what planning you mean? I do it without planning and haven't had an issue.
- Graziano_M 5y ago
  Planning my social life around it. I'm not as fun at dinner if all I can have is water.

Gregam3 5y ago

I love fasting and typically I have one meal and fast for 22 hours a day, but please be careful with multi day fasting. I drink a lot of water and on two occasions on 60 hour fasts I passed out cold, falling to the ground and chipping one of my front teeth in the process, but it could have ended much worse. I eventually figured out I was not consuming enough electrolytes relative to my water consumption, I still recommend long term fasts but please do more research than I did and be careful. I have kept that chip in my tooth to this day to remind me my naivety and how lucky I was.

gcheong 5y ago

The study in the OP is specific to alternate day fasting though, which is generally much more tolerable than straight-up multi-day fasts, and can be done over a much longer term.

vagab0nd 5y ago

How do you overcome upset stomach? If I don't eat for half a day my stomach starts to hurt.