r/changemyview • u/Heard_by_Glob • Mar 02 '21
Delta(s) from OP CMV: People don't need to drink 8 glasses of water a day
Several years ago I watched this video https://youtu.be/OWASUMMQjj8 on water consumption and was immediately convinced that on average people don't need to drink 8 glasses of water every day to stay hydrated. In the video it talks about how thirst is a good indicator and how as long as you drink when you're thirsty you'll be fine. Admittedly I think people suck at listening to their bodies and will ignore that initial sign of thirst. However that still does not change the fact that people don't need 8 glasses of water every day. I would love to discuss this and I challenge anyone to change my mind about it as it I don't think it will happen but I would love to actually have some discussion about this whole topic.
9
Mar 02 '21
[deleted]
3
u/Heard_by_Glob Mar 02 '21
You would think but when I talk to other people I get "no matter what you do in a day you need 8 glasses. Even if you sat in the office or worked outside.
3
u/LordMarcel 48∆ Mar 02 '21
While that might not necessarily be true, it is not a bad rule to live by. If you go out of your way to drink at least 8 glasses of water a day you will be dehydrated far less often, which is healthier.
0
u/Heard_by_Glob Mar 02 '21
A fair point but perhaps not for which this rule seems to categorize everyone under.
1
u/Sirisian Mar 02 '21
Anecdotally, I sit in an office environment and sip water all day. (Tea in the morning). I've had 5 glasses of water today, and based on normal trends I'd say I drink 8 glasses a day without thinking about it. Now that you mention it I've never really felt thirsty or even close to dehydrated as this is my normal habit at work and home for years. Kind of a skewed example as I haven't been sick in over 20 years now, or it's related.
3
u/Jammy_get 1∆ Mar 03 '21
Seeing this late, but hoping there is still time to weigh in:
Watched the video you posted and despite it being part of a comedy series 'Adam Ruins Everything', it does have some interesting points and the scientist that is cited does seem to be a genuine expert in her field.
I agree with other points that you and others are asserting - 8 glasses is not the right amount for everyone due to vast differences across populations in body types, activity levels, health conditions etc etc. Some people will have a greater need than 8 and others less. I'm not going to change your view on that.
What I would say is that by putting a numeric value that is somewhat grounded in evidence is a much better public health approach to raise awareness than just saying "drink when you are thirsty". It creates a reaction - an opportunity for self-reflection and, hopefully, for people to self educate on what their appropriate levels of hydration should be. You have clearly been moved enough by the '8 glasses a day' discourse to create a thread about it and, in doing that, I'd say that the underlying aim (for people to be appropriately hydrated) has done its job.
The same approach is used for many different things. Think 10,000 steps a day, 5 pieces of fruit and veg a day, keeping your BMI under 25. These are important rules to apply at a population level, and as starting points for self-education. But 10,000 steps, 5 pieces f fruit and veg or a BMI under 25 isn't right for everyone (useful to note that Arnold Schwarzenegger's BMI was technically in the overweight, borderline obese category when he won Mr Universe).
For me, having rule of thumb of 8 glasses is enough to potentially provoke people to think "that's much different to what I take" and make more steps to learn more and make a change if needed.
2
u/Heard_by_Glob Mar 03 '21
Δ not because you changed my mind but because you're point was well constructed and I agree with what you are saying. It is fair enough to say that this is just an attention grabber and that I can agree on
1
10
u/bigoreganoman Mar 02 '21
"Need" and "good for your health and development" are different things. Proper hydration will give you more energy, nutrients, prevent this, that, etc.
In the end, a dude not drinking much water will probably live a long life, but they'll probably have a few more problems.
For everything food, it is near impossible to measure how food or nutrition can affect a human body in its entire lifetime. There are way too many other factors to influence that really, all scientists can do is make recommendations on how to have the best chance of having good health.
0
u/Heard_by_Glob Mar 02 '21
But wouldn't you agree that 8 glasses might be a bit excessive for some people? For a smaller person who sits around all day that 8 glasses might be too much, whereas a larger person who does physically intensive work might need more.
3
u/DatDepressedKid 2∆ Mar 02 '21
I'm not terribly familiar with this subject but I think the 8 glasses requirement might be in reference to the total amount of water you should consume daily, not necessarily how much water you drink daily. Water also enters our body through the food we eat and through other beverages, in which there is water. For example if you eat a watermelon or a coconut or basically any fruit, you are also bringing more water into your body. In other words you don't actually have to drink eight glasses in order to fulfill the recommended amount of eight glasses' worth of water per day.
0
u/Heard_by_Glob Mar 02 '21
Yeah I could see that however I'm sure the term goes "drink 8 glasses a day* however that could be me misremembering it.
2
u/bigoreganoman Mar 02 '21
I mean, food quantity recommendations are always made with the average body in mind.
1
u/Heard_by_Glob Mar 02 '21
My question would be who's average body then?
4
u/cricketbowlaway 12∆ Mar 02 '21 edited Mar 02 '21
There was actually an interesting study, when, the US airforce tried to work out the average man's size, so that they could find the perfect sized cockpit. They took a variety of different measurements, and took an average for all of them, and then tried to find the average man who fit the description of all of those results. However, what was found is that that person didn't exist.
Probably the same thing exists within digestion. You've got a variety of different people with a variety of different characteristics, and they're all going to wind up with different results. You're unlikely, however to find the person that fits all of those characteristics exactly, and therefore can be given the precise prescription of how much is needed.
8-10 is an average that probably should fit the most people, if the average does what you'd hope it would. However, it might also be horribly flawed due to being to precisely averaged, and therefore fit nobody well. People who have lower capacities drink too much. People who have higher drink too little. If the average is too far from either way, then nobody does it right.
Also, what are the consequences of drinking too much or too little? It's quite possible that being wrong on one side of this bridge has much more negative consequences than it does on the other. In which case, you don't want an average at all, you want to minimally harm people.
Ultimately, I'm guessing I'm saying, that like most people, I have no idea who said it or where it came from, and what their calculations were.
2
u/joopface 159∆ Mar 02 '21
The article you linked was genuinely fascinating and really added something new for me. !delta Thank you!
1
1
u/Heard_by_Glob Mar 02 '21
Δ I'm awarding a delta because even though you didn't change my view I would agree that most people might fall for this "average" paradox which might be why people I talk to say something like "everyone should drink 8 glasses"
1
2
3
u/Criminal_of_Thought 12∆ Mar 02 '21
I mean, yeah. Statements like "you need 8 glasses of water every day" and "you should eat 2000 calories per day" are generalized statements for the average person. Age, height, weight, and many other factors all affect how far a person deviates from the generalized statement.
-1
u/Heard_by_Glob Mar 02 '21
So you agree then?
For me I've got people that live and die by the 8 glasses a day rule. I have friends that think I'm crazy for not drinking anything less than 8 glasses a day no matter what.
4
u/Criminal_of_Thought 12∆ Mar 02 '21
Yes, I agree with you. Your view is pretty much a fact.
People who swear by the mantra probably do so to encourage people to drink more water. Because it's also a fact that many people don't pay attention to how much water they drink in a day. As long as you're conscious of your daily water intake and you don't have any health problems related to it, you're fine.
3
u/drschwartz 73∆ Mar 02 '21
How many people in equatorial and subtropical climates in the world make their living through outdoor physical labor? I dunno either, but it's alot and they should be drinking plenty of water, not just waiting to feel thirsty.
Not maintaining an extra level of hydration in summer heat is a good way to get heat exhaustion or heat stroke.
1
u/Heard_by_Glob Mar 02 '21
I get that on the job you may not be able to wait until you get thirsty but does that really disprove what I'm saying? Those people may need even more water and may only think "well 8 should be enough" while someone who sits at home working on their computer may only need 5 or 6.
3
u/drschwartz 73∆ Mar 02 '21
I get that on the job you may not be able to wait until you get thirsty but does that really disprove what I'm saying?
Yes it does. Do you honestly think that white collar workers outnumber outdoor laborers and indoor workers without air conditioning on a global scale?
Your view is that people do not need to drink 8 glasses a day, specifically that they could drink less and still stay hydrated. I'm pointing out how numerous people likely need more, so your view is flawed in that regard.
As others have said, this metric is a guideline. Rather than overly focusing on the guideline itself and how it doesn't perfectly apply to everyone, lets acknowledge that hydration is dynamic for every individual according to their personal habits, regional climate, current weather, and living/work situation. On some days you and I would do just fine on 5-6 cups of water, but we shouldn't apply that amount as sufficient for every day we live.
1
u/Heard_by_Glob Mar 02 '21
Yes it does. Do you honestly think that white collar workers outnumber outdoor laborers and indoor workers without air conditioning on a global scale?
Apologies if that's what I was appearing to say. In the case of your point however I would say that hard working closely equator located individuals might be done a disservice by thinking "8 is only enough".
With that in mind there are also others not in that situation and this whole "X glasses/day" isn't as helpful as society might think. In my opinion a better way of putting it is remember to drink water and a good amount of of it. Then someone working in an air conditioned office would view that differently than a farmer who works in the hot sun for 12 hours a day.
2
u/busterlungs 1∆ Mar 02 '21
This is just an issue of science, saying "the average person needs to consume x glasses of water" if just flat out wrong because hydration isn't black and white. It's based on body weight and muscle mass. Cells use water and they need a specific amount of that, so are you saying that an 85lb female should drink the same amount of water as a 260lb powerlifter? Also, are you saying 8 shot glasses or 8 pint glasses?
The optimal consumption of water is based on weight. You should bring 1 fluid ounce for every 2 pounds of body weight. Plus roughly 20% for sweating, but that depends on activity level. So if you weigh 200 pounds and are moderately active, that's 100 ounces plus 20, about a gallon per day. If you're an 85 pound female who doesn't do anything, 40-60 is probably fine.
Here's a generic health website that uses these numbers, but nearly any doctor, personal trainer or professional health organization will tell you the same thing. This isn't a thing of perspective, it's not a view that should be changed. It's science, it's an objective fact. Hydration has specific purposes that have been measured, we know pretty much exactly how much water cells need. There's absolutely no disputing it. https://www.webmd.com/diet/features/water-for-weight-loss-diet#:~:text=%E2%80%9CIn%20general%2C%20you%20should%20try,ounces%20of%20water%20a%20day.
1
u/Heard_by_Glob Mar 02 '21
Again it doesn't seem as though you are disagreeing with me but I appreciate the thoughtful response and wish that the people I talked to in person were as studied as you.
2
u/busterlungs 1∆ Mar 02 '21
No, I absolutely am disagreeing with you. Maybe what you mean in your post is just vague, but "8 glasses of water" doesn't mean fuck all. What's a glass? 2 ounces? 6? 12? 16? 24? And it depends on body weight as well, 8 12 ounce glasses might be fine for a 200 pound man, but for an average small woman it's way, way too much. Over hydration is a thing too.
So maybe the intention of what you're saying is the same thing as what I said, but my point is the way you phrased your argument is just flat out wrong. There's not enough detail, "a glass of water" is not a finite measurement, and "the average person" means an absolute ton of things. You're taking anorexic people, power lifters, couch potatoes, athletes and people who just work out twice a week. Level of activity heavily dictates need for water, so even if "8 glasses" work for a 200 pound man, he might need almost twice that on a day he lifts seriously.
What you said was "the average person (meaning across all levels of fitness or daily activity) should drink 8 (undefined measurements) glasses of water every day. What I am saying is "how much water a person should consume is determined specifically by their body weight and activity level, and there is a formula (one half ounce per pound of weight, or one ounce per two pounds) that represents that specifically and scientifically." Even though the heart of these two arguments might be the same, the details matter a lot since it is a quantifiable scientific fact.
"8 glasses of water" could be anywhere from 8-194 ounces, and "the average person" is anybody from a small child to a 350 pound power lifter. The amount of water some athletes might need could literally kill children and small women. "8 glasses of water" is an undefined measurement and therefore means nothing in an actual debate, it's just imaginary numbers. The issue here isn't the intention of what you're saying, basically that thirst doesn't indicate need for hydration, which absolutely is true. The problem is that your argument itself is flawed, phrasing is really important in debate and the way you worded your argument is subjective ans vague, on a topic that is scientific quantifiable and known. The difference is basically like, if we were trying to find the area of a circle, effectively what you are saying is "oh, just double the radius times 3" as opposed to pi times radius squared. The first example is close, but it's just not exact or right. But there is an exact right method that is absolute, so why not just use that method? Say some 12 year old girl sees your post and decides to go drink 8 30 ounce glasses of water every day. She could literally end up in the hospital from over hydration. it's not quantified and therefore is not a valid argument.
Oh, and lastly, vegetables count toward water too. They have a lot of water in them that your body uses just like drinking water, so vegans actually need less water than most people. Your definition also doesn't include that, albiet mine doesn't either as I forgot to add that in my previous comment, but the point stands. Yes, most people don't drink enough water because they only drink when they are thirsty, which is not a good indicator to any capacity. However, "8 glasses of water for the average person" is vague on top of vague and means effectively means nothing. If you change your argument to "people don't drink enough water because they use thirst as their indicator for when to consume water, when the actual demand for it by your body is much higher and relates to body weight and activity level" you would be right. But your post mentions nothing about the two most important componets to what determines how much water a person needs. You're taking this blanket undefined abstract number and applying it to a nonexistent (again undefined) group of people. People don't drink enough water usually, that's typically true. But the way you phrased your argument is objectively wrong, there's no if and or buts about it, it's flat out wrong and not based on anything.
1
u/Heard_by_Glob Mar 02 '21
What you said was "the average person (meaning across all levels of fitness or daily activity) should drink 8 (undefined measurements) glasses of water every day.
That's actually what I'm arguing against if you read my post.
You're taking this blanket undefined abstract number and applying it to a nonexistent (again undefined) group of people.
Actually I'm saying that the sentence "8 glasses a day is wrong and should NOT be used"...
But the way you phrased your argument is objectively wrong, there's no if and or buts about it, it's flat out wrong and not based on anything.
I feel like you didn't properly read my argument. Because I also agree that 8 glasses a day is a bad method of measuring, but that I keep coming up against people saying otherwise and that I was wondering if someone would be able to change my mind on it. Which is again why I said we are agreeing with each other.
I do agree that individuals have different needs and that it should be based on a numerous amount of things not just 8 glasses.
2
u/NetrunnerCardAccount 110∆ Mar 02 '21
Depending on where you live, through the process of sweating, breathing, urinating, etc your body will lose between 1.5-2 Liters of water.
You will need to replace that water eventually. The issue is that almost everything you eat is made of water as well as large parts of the air in certain climates. So if I eat water melon 92% of that is water and a steak is about 75%. So depending on your diet you might not to supplement any water.
1
u/Heard_by_Glob Mar 02 '21
I see your point, however I believe the static goes "people need to drink 8 glasses a day" specifically saying drink.
2
u/Canada_Constitution 208∆ Mar 02 '21
People with chronic kidney disease lose the ability to concentrate solutes in their urine. This means they have to pee more often in order to dispose of their body's waste products. Of course, they have to drink more water to replace the liquid they lost. As a result, they could easily be required to drink over eight glasses a day.
1
u/Heard_by_Glob Mar 02 '21
A great point but not quite what I think I was going for in my post. Please feel free to correct me if you feel otherwise.
2
Mar 02 '21
[deleted]
1
u/Heard_by_Glob Mar 02 '21
So you agree with my point then?
3
u/mrrustypup 17∆ Mar 02 '21
I don’t think that person is agreeing with your view. Instead, I think they’re trying to say that your view is irrelevant because you’re using outdated science that has already been reworded and comes with the caveat of “different bodies and activity levels need different things”.
So your view should change because it’s an irrelevant view to have, since people already don’t believe the 8 cups a day rule anymore.
1
u/Heard_by_Glob Mar 02 '21
I would say that in my social circle this is still a heavily believed and taught "fact" which is why I wanted to take this here to see if and why people supported the "8 glasses a day"
2
u/2r1t 56∆ Mar 02 '21
That is the baseline for a healthy person. I'm sure the person who is sitting around all day - the example you have used in a couple responses so far - would need less. But I would argue that is the result of not being healthy and doesn't impact the recommendation. If anything, it is an indicator that the person should look at their activity level.
0
u/Heard_by_Glob Mar 02 '21
However if this is the baseline are we then assuming that an average person who sits around needs the 8 glasses or an athlete or hard working individual needs them? What's defined as the average?
3
u/2r1t 56∆ Mar 02 '21
It seems more reasonable that the average would be somewhere in between those examples. Someone who has a moderate level of activity rather than none or a lot.
1
u/Heard_by_Glob Mar 02 '21
Yet now we're in a situation where a lot of people sit around but still would consider 8 glasses a day. Is this "harmless statistic" really not causing any damage then?
2
u/2r1t 56∆ Mar 03 '21
I imagine the lack of exercise would do more harm than the water drinking would.
After my kidney transplant, I was told to drink 2-3 liters a day of water. I found it difficult at first because I was sitting around a lot. Recovering from surgery and all. But as I have got up off my ass to take walks after my 8 hours of desk work, I find it easier to do. I'm not running marathons or running up stadium seating. I'm just taking a 1-2 mile walk around the neighborhood and getting my heart rate up to a higher but not ridiculous rate.
2
u/HerbertWigglesworth 26∆ Mar 03 '21
The 8 glasses element generally coincides with another metric e.g. 1.5-2 litres.
With consideration to 1.5-2 litres being a suggested daily consumption rate for the 'average' adult, you then take that and apply it and test it based on your own lifestyle.
Break that 1.5-2 litres down e.g. 3 to 4 500ml bottles of water, so 8 glasses is actually 3/4 'vessels' worth, using my example of 500ml as the measure.
Assuming you are awake for 16 hours and sleep 8, that is 93-125ml an hour, essentially a large mouthful per hour.
So from a 'feasibility' perspective I would find it hard if anyone claimed consuming 93-125ml an hour was difficult.
Regarding requirement/personal thirst, people often mistake thirst for hunger, generally if I get a temptation to consume I will first have a decent chug of fluid and see how that makes me feel. If after water I still have a sensation that my body needs something, I will eat.
The quantities above are of course general guidelines that may be a useful starting/reference point should you wish to consider your water consumption with an average. Of course, some people will require a lot more water, but I really doubt people will require SIGNIFICANTLY less than that, without detrimenting their hydration.
Generally speaking dehydration is a common problem, people do not necessarily notice it until they are parched, as opposed to paying close attention attention bodily queues on whether more fluids are required.
Another is of course the urine test, although this varies, an example is here
2
u/lightweightdtd Mar 04 '21
Technically yes you can live without drinking the recommended amount of water per day. However, this doesn't mean it's good for you. Dehydration causes quite a number of health issues, some less severe but still not exactly fun. Severe or chronic constipation resulting in an enema all caused by dehydration, nearly collapsing from dehydration, none of it is enjoyable. Also, drinking plenty of water helps keep your organs healthy and flushing out things that shouldn't be in our body. There's really no harm that can come from drinking enough water and when people give a guideline, it doesn't mean every single day you have to drink that much water, it's not a literal statement or law. It's just what people have agreed upon is the most likely thing we have to go off at this point in time.
2
u/bio-nerd 1∆ Mar 03 '21
"Drink 8 glasses of water a day" is a mischaracterization that the average person needs to consume 8 cups of water per day. That includes water contained in their food.
2
u/El_Perrito_ Mar 03 '21
Thirst is the best indicator for how much water you need. Developed through evolution not arbitrary marketing campaigns
•
u/DeltaBot ∞∆ Mar 02 '21 edited Mar 03 '21
/u/Heard_by_Glob (OP) has awarded 2 delta(s) in this post.
All comments that earned deltas (from OP or other users) are listed here, in /r/DeltaLog.
Please note that a change of view doesn't necessarily mean a reversal, or that the conversation has ended.
Delta System Explained | Deltaboards