7 ms·

I have wondered why humans don't really have much of a water buffering capacity, mostly prompted by a line in Dune about "water-fat" Atreides. Would be great to

by hoseja 5y ago

I have wondered why humans don't really have much of a water buffering capacity, mostly prompted by a line in Dune about "water-fat" Atreides. Would be great to be able to chug like two liters of water and go about your day reasonably hydrated.

dukeyukey 5y ago
> Would be great to be able to chug like two liters of water and go about your day reasonably hydrated. During Ramadan (not Eid as someone pointed out!), most Muslims refrain from eating or drinking during the day, and Muslims are highly overrepresented in warmer countries, so it's definitely possible, though maybe not comfortable.
- frutiger 5y ago
  > During Eid During the lunar month of Ramadan. Eid is the first day of the following month when Muslims celebrate the end of Ramadan. (There is an unrelated separate Eid at a different point in the year).
- wincy 5y ago
  When I lived with Saudis during Ramadan in college, their fasting strategy was mostly to just sleep all day and wake up a little before sundown. I ate some really delicious food during that month!
  - Aperocky 5y ago
    Does that mean for a whole month the entire country/Muslim world does the night shift?
    - mschild 5y ago
      I have often visited Morocco and lived in Malaysia for some time. Sort of, yes. During noon and afternoon most shops, restaurants, and other places were closed. Certain essential things were open. There was also a divide between rural vs urban, with urban have more open stores. Especially in Morocco this didn't seem too uncommon even outside of Ramadan though as its often simply too hot to really work during the day.
    - abdullahkhalids 5y ago
      No. Rather productivity is down 50% or more for the entire month. Imagine two civilizations otherwise equal. One works 12/12=100% of the year, and the other 11.5/12=96% of the years. Then compound the gains over 14 centuries!
      - jopsen 5y ago
        You're assuming no wars or other inefficiencies... In practice there is probably plenty of inefficiencies to go around. Maybe less today, but 14 centuries ago.
    - umeshunni 5y ago
      Depends on the country. When we lived in Saudi, during Ramadan most stores took the morning off and were open well into the night (like midnight). Many businesses (banks etc) did a morning shift (9-1) and then an evening shift (6-10). e.g. here's a Facebook Post from IKEA Qatar on their store hours during Ramadan: https://m.facebook.com/IKEAQatar/photos/pb.577718508978609.-2207520000.1467441474./1031546840262438/?type=3&source=43 https://m.facebook.com/IKEAQatar/photos/pb.577718508978609.-...
- watwut 5y ago
  Not just uncomfortable. I remember reading that women who are in early stage of pregnancy during that time are more likely to have disabled kids. (Women who know about pregnancy dont have to fast, so it affects early stages the most).
sva_ 5y ago
I think it may have to do with our gut size decreasing throughout evolution. https://en.wikipedia.org/wiki/Expensive_tissue_hypothesis https://en.wikipedia.org/wiki/Expensive_tissue_hypothesis
FridayoLeary 5y ago
I can drink two litres in a go (with difficulty perhaps) and fast the whole day, that's no great feat.
- csomar 5y ago
  You can drink two liters but you can't store them. You'll be going to the toilette pretty soon and losing it.
  - hutzlibu 5y ago
    Have you tried? I did on some occasions on a hot day, before going off to some activity - and it does not last the whole day - but it definitely last some time.
    - johnchristopher 5y ago
      Perspiration then ?
      - hutzlibu 5y ago
        Sure. Also you hydrate your whole body so all the processes that need water have water. And then you can last some time without water(without perceived negative effect), but I do prefer to always have water around.
    - csomar 5y ago
      half a liter and I'm going to the WC in 15 minutes. But then I weigh little. If you drink 2 liters and don't need to check the toilette for several hours, I'd visit a doctor.
      - hutzlibu 5y ago
        Whats wrong with going to the toilet? Thats part of the body process to flush out unwanted substances. So if you drink enough, you flush out enough - and then you do not need so much water anymore. So you can drink lots of water and then not needing more water. So the storage of water you have when you are hydrated, lasts some time. That was my point. But you are correct, that when you drink more and more, despite your body being already hydrated - then it pretty much comes out like it is soon after.
Kirth 5y ago
We do store water in our fat. Dry fasting will cause your body to more aggressively break down the fat to get this water. Unfortunately, your body won't/can't always break down fat.
- fpoling 5y ago
  In Russia there are dry fasting resorts that allow people to fast without drinking water for 7-11 days under medical supervision. Most people do it for medical conditions, but some indeed as a way to quickly drop weight. Note that such fasting does not avoid all contacts with water. People still bath and brush teeth.
deleted 5y ago
[deleted]
hammock 5y ago
In the outdoors community, there is an emerging breed of ultralight backpacker that wants to shed carried weight so much that they refuse to carry water. Instead, they chug as much as they need when they reach a water source, and continue on the trail without any reserve in water bottles.
- mc32 5y ago
  So it’s in their bodies instead of carried on their bodies? Maybe the few grams of plastic for the container means that much to them? It’s seems like this is kind of related to where bikers (cyclists) pay double for a component to save 100 grams instead of losing a bit of body weight.
  - adrianN 5y ago
    There is a big difference between carrying weight on or back and carrying it inside your body.
    - gruez 5y ago
      I suspect the amount you can "carry" in your body (ie. not including the amount you'll urinate 1 hour later) is in the order of 1-2kg tops, so ease of carrying isn't noticeable.
      - adrianN 5y ago
        1-2kg can be a big fraction of the total weight an ultralight backbacker packs. I'm by no means an ultralight backpacker and my backpacks are usually around 10-15kg. A 10% saving is definitely noticable on longer hikes.
    - mnw21cam 5y ago
      Which is why when I went hiking, I attached a couple of home-made carriers to the front straps of my rucksack. One to carry a water bottle, and the other to carry a camera. Having some of the weight on the front (rather than all of it on the back) helps. There's (quite old now) research that shows that people in Africa who carry immense loads on their heads actually have a more efficient walking gait than people who carry loads on their backs.
roenxi 5y ago
Water is pretty heavy (eg, denser than wood, denser than oil, denser than fat, etc). Weight is costly (eg, mv^2 energy to accelerate). I guess human bodies have spent a lot of time trying to find the minimum amount of water necessary rather than trying to build up a reserve. The little micro-optimisations add up over time. The penalty for excess weight doesn't have to be large before evolution tries to get rid of it. Historically, fat people are an anomaly.
gregwebs 5y ago
Actually this very practice is described in the book "The Old Way". The natives in a dry region in Africa would drink massive amounts at a watering hole before setting off for a journey. It was probably more than 2 liters. I try to take a similar approach when hiking of drinking as much water as I can before starting a hike. In a hot and dry climate you don't end up urinating out as much as you might think. Exposure to this practice over time in a particular environment might be able to alter gene expression to better support the practice much like the hunter reflex develops with cold exposure. People often make the mistake of thinking their personal modern experience is close to some human limit. "The Old Way" also points out that persistence hunting (mentioned in this article) could only be used under particular environmental conditions (mud after rain that slows down animals) with a particular animal that overheats more than others so it didn't seem a reliable hunting method.
- systemvoltage 5y ago
  To others reading this there needs to be a big bold WARNING: Do not drink liters of water as people have died doing just that. Google it and you’ll find horror stories of people in competition to chug tons of water only to make an ER trip and die on the way. There is a myth on the internet that drinking shitload of water beyond comfort is acceptable and has zero risks because hey it’s just water right? Here is some literature: https://www.scientificamerican.com/article/strange-but-true-drinking-too-much-water-can-kill/ https://www.scientificamerican.com/article/strange-but-true-...
  - msrenee 5y ago
    To be more precise: do not chug liters of water without supplemental electrolytes. What kills people is the fact that salts are water-soluble and are flushed out as you drink water. It's not the volume of water that's inherently dangerous. It's that it flushes out water-soluble electrolytes that are necessary to muscle function.
  - gregwebs 5y ago
    I can't edit my comment anymore but did upvote yours. I agree with those warnings about imitating this practice. My "drinking as much water as I can" is perhaps 1 liter, much less than what seemed to be described in "The Old Way". In the article you point to the main issue seems to come from inhibition of urination. I think native people knew their bodies extremely well and could avoid any problem here whereas in modern times we have been training ourselves since being a small child to ignore or hold back urination. Combining that with other suppressors mentioned in that article can end in tragedy.
jvanderbot 5y ago
We probably could if we didn't sweat. Sweating (combined with hairless-ness) is a competitive advantage in thermal regulation, that enables long, long runs during hunting (or maybe foraging too, I don't know). But, you lose a lot of water.
- chaorace 5y ago
  I wonder if our closest living relatives have lesser or greater water capacities? You'd think persistence hunting in the savannah would select pretty hard for such an advantage, but perhaps that particular need was already offset by early tool-use? (portable water containers, wet furs)
layla5alive 5y ago
I regularly do that. I'm surprised to hear it stated as something you assume to not be possible. I also eat a single meal per day.

by hoseja 5y ago

dukeyukey 5y ago

> Would be great to be able to chug like two liters of water and go about your day reasonably hydrated. During Ramadan (not Eid as someone pointed out!), most Muslims refrain from eating or drinking during the day, and Muslims are highly overrepresented in warmer countries, so it's definitely possible, though maybe not comfortable.

frutiger 5y ago
> During Eid During the lunar month of Ramadan. Eid is the first day of the following month when Muslims celebrate the end of Ramadan. (There is an unrelated separate Eid at a different point in the year).
wincy 5y ago
When I lived with Saudis during Ramadan in college, their fasting strategy was mostly to just sleep all day and wake up a little before sundown. I ate some really delicious food during that month!
- Aperocky 5y ago
  Does that mean for a whole month the entire country/Muslim world does the night shift?
  - mschild 5y ago
    I have often visited Morocco and lived in Malaysia for some time. Sort of, yes. During noon and afternoon most shops, restaurants, and other places were closed. Certain essential things were open. There was also a divide between rural vs urban, with urban have more open stores. Especially in Morocco this didn't seem too uncommon even outside of Ramadan though as its often simply too hot to really work during the day.
  - abdullahkhalids 5y ago
    No. Rather productivity is down 50% or more for the entire month. Imagine two civilizations otherwise equal. One works 12/12=100% of the year, and the other 11.5/12=96% of the years. Then compound the gains over 14 centuries!
    - jopsen 5y ago
      You're assuming no wars or other inefficiencies... In practice there is probably plenty of inefficiencies to go around. Maybe less today, but 14 centuries ago.
  - umeshunni 5y ago
    Depends on the country. When we lived in Saudi, during Ramadan most stores took the morning off and were open well into the night (like midnight). Many businesses (banks etc) did a morning shift (9-1) and then an evening shift (6-10). e.g. here's a Facebook Post from IKEA Qatar on their store hours during Ramadan: https://m.facebook.com/IKEAQatar/photos/pb.577718508978609.-2207520000.1467441474./1031546840262438/?type=3&source=43 https://m.facebook.com/IKEAQatar/photos/pb.577718508978609.-...
watwut 5y ago
Not just uncomfortable. I remember reading that women who are in early stage of pregnancy during that time are more likely to have disabled kids. (Women who know about pregnancy dont have to fast, so it affects early stages the most).

sva_ 5y ago

I think it may have to do with our gut size decreasing throughout evolution. https://en.wikipedia.org/wiki/Expensive_tissue_hypothesis https://en.wikipedia.org/wiki/Expensive_tissue_hypothesis

FridayoLeary 5y ago

I can drink two litres in a go (with difficulty perhaps) and fast the whole day, that's no great feat.

csomar 5y ago
You can drink two liters but you can't store them. You'll be going to the toilette pretty soon and losing it.
- hutzlibu 5y ago
  Have you tried? I did on some occasions on a hot day, before going off to some activity - and it does not last the whole day - but it definitely last some time.
  - johnchristopher 5y ago
    Perspiration then ?
    - hutzlibu 5y ago
      Sure. Also you hydrate your whole body so all the processes that need water have water. And then you can last some time without water(without perceived negative effect), but I do prefer to always have water around.
  - csomar 5y ago
    half a liter and I'm going to the WC in 15 minutes. But then I weigh little. If you drink 2 liters and don't need to check the toilette for several hours, I'd visit a doctor.
    - hutzlibu 5y ago
      Whats wrong with going to the toilet? Thats part of the body process to flush out unwanted substances. So if you drink enough, you flush out enough - and then you do not need so much water anymore. So you can drink lots of water and then not needing more water. So the storage of water you have when you are hydrated, lasts some time. That was my point. But you are correct, that when you drink more and more, despite your body being already hydrated - then it pretty much comes out like it is soon after.

Kirth 5y ago

We do store water in our fat. Dry fasting will cause your body to more aggressively break down the fat to get this water. Unfortunately, your body won't/can't always break down fat.

fpoling 5y ago
In Russia there are dry fasting resorts that allow people to fast without drinking water for 7-11 days under medical supervision. Most people do it for medical conditions, but some indeed as a way to quickly drop weight. Note that such fasting does not avoid all contacts with water. People still bath and brush teeth.

deleted 5y ago

[deleted]

hammock 5y ago

In the outdoors community, there is an emerging breed of ultralight backpacker that wants to shed carried weight so much that they refuse to carry water. Instead, they chug as much as they need when they reach a water source, and continue on the trail without any reserve in water bottles.

mc32 5y ago
So it’s in their bodies instead of carried on their bodies? Maybe the few grams of plastic for the container means that much to them? It’s seems like this is kind of related to where bikers (cyclists) pay double for a component to save 100 grams instead of losing a bit of body weight.
- adrianN 5y ago
  There is a big difference between carrying weight on or back and carrying it inside your body.
  - gruez 5y ago
    I suspect the amount you can "carry" in your body (ie. not including the amount you'll urinate 1 hour later) is in the order of 1-2kg tops, so ease of carrying isn't noticeable.
    - adrianN 5y ago
      1-2kg can be a big fraction of the total weight an ultralight backbacker packs. I'm by no means an ultralight backpacker and my backpacks are usually around 10-15kg. A 10% saving is definitely noticable on longer hikes.
  - mnw21cam 5y ago
    Which is why when I went hiking, I attached a couple of home-made carriers to the front straps of my rucksack. One to carry a water bottle, and the other to carry a camera. Having some of the weight on the front (rather than all of it on the back) helps. There's (quite old now) research that shows that people in Africa who carry immense loads on their heads actually have a more efficient walking gait than people who carry loads on their backs.

roenxi 5y ago

Water is pretty heavy (eg, denser than wood, denser than oil, denser than fat, etc). Weight is costly (eg, mv^2 energy to accelerate). I guess human bodies have spent a lot of time trying to find the minimum amount of water necessary rather than trying to build up a reserve. The little micro-optimisations add up over time. The penalty for excess weight doesn't have to be large before evolution tries to get rid of it. Historically, fat people are an anomaly.

gregwebs 5y ago

Actually this very practice is described in the book "The Old Way". The natives in a dry region in Africa would drink massive amounts at a watering hole before setting off for a journey. It was probably more than 2 liters. I try to take a similar approach when hiking of drinking as much water as I can before starting a hike. In a hot and dry climate you don't end up urinating out as much as you might think. Exposure to this practice over time in a particular environment might be able to alter gene expression to better support the practice much like the hunter reflex develops with cold exposure. People often make the mistake of thinking their personal modern experience is close to some human limit. "The Old Way" also points out that persistence hunting (mentioned in this article) could only be used under particular environmental conditions (mud after rain that slows down animals) with a particular animal that overheats more than others so it didn't seem a reliable hunting method.

systemvoltage 5y ago
To others reading this there needs to be a big bold WARNING: Do not drink liters of water as people have died doing just that. Google it and you’ll find horror stories of people in competition to chug tons of water only to make an ER trip and die on the way. There is a myth on the internet that drinking shitload of water beyond comfort is acceptable and has zero risks because hey it’s just water right? Here is some literature: https://www.scientificamerican.com/article/strange-but-true-drinking-too-much-water-can-kill/ https://www.scientificamerican.com/article/strange-but-true-...
- msrenee 5y ago
  To be more precise: do not chug liters of water without supplemental electrolytes. What kills people is the fact that salts are water-soluble and are flushed out as you drink water. It's not the volume of water that's inherently dangerous. It's that it flushes out water-soluble electrolytes that are necessary to muscle function.
- gregwebs 5y ago
  I can't edit my comment anymore but did upvote yours. I agree with those warnings about imitating this practice. My "drinking as much water as I can" is perhaps 1 liter, much less than what seemed to be described in "The Old Way". In the article you point to the main issue seems to come from inhibition of urination. I think native people knew their bodies extremely well and could avoid any problem here whereas in modern times we have been training ourselves since being a small child to ignore or hold back urination. Combining that with other suppressors mentioned in that article can end in tragedy.

jvanderbot 5y ago

We probably could if we didn't sweat. Sweating (combined with hairless-ness) is a competitive advantage in thermal regulation, that enables long, long runs during hunting (or maybe foraging too, I don't know). But, you lose a lot of water.

chaorace 5y ago
I wonder if our closest living relatives have lesser or greater water capacities? You'd think persistence hunting in the savannah would select pretty hard for such an advantage, but perhaps that particular need was already offset by early tool-use? (portable water containers, wet furs)

layla5alive 5y ago

I regularly do that. I'm surprised to hear it stated as something you assume to not be possible. I also eat a single meal per day.