"Adequate Intakes (AI) have been defined derived from a combination of observed intakes in population groups with desirable osmolarity values of urine and desirable water volumes per energy unit consumed. The reference values for total water intake include water from drinking water, beverages of all kind, and from food moisture and only apply to conditions of moderate environmental temperature and moderate physical activity levels (PAL 1.6). [...] Available data for adults permit the definition of AIs as 2.0 L/day (P 95 3.1 L) for females and 2.5 L/day (P95 4.0 L) for males."
"The minimum water requirement for fluid replacement for a 70kg human in a temperate zone equates to 3L per day, or 42.9mL/kg [according to the Tropical Agriculture Association]. Minimum requirements for an individual the same size but in a tropical zone equates to 4.1 to 6L/day"
"Age and gender specific Adequate Intakes (AI) for water were established in 2004 by the [United States] Food and Nutrition Board (5). The Dietary Reference Intakes (DRI) for water are [for ages 19 and older] Men 3.7 L/day Women 2.7 L/day"
>The well-known “8 x 8” rule — you should drink eight 8-ounce glasses of water a day — is not only daunting, it’s unfounded. In fact, nobody is sure where the idea came from, and science doesn’t support it. “It has no basis in fact,” says Michael Farrell, a professor at Monash University in Australia, who studies how the brain responds to thirst and other sensations.
> The average adult woman should consume about 11.4 cups of fluid per day (a cup equals 8 ounces) and men should consume 15.6 [...] Subtracting the 20% of water consumed through food, that means the average woman should drink about 9.1 cups of fluid daily, and a man should drink about 12.5.
8 times 8 ounces per day of fluid is 64 ounces of fluid per day, whereas ~9 cups per day of fluid times 8 ounces/cup is ~72 ounces of fluid per day. So isn't the recommendation actually _more_ than the 8x8 adage?
Many people believe that the source of this myth was a 1945 Food and Nutrition Board recommendation that said people need about 2.5 liters of water a day. But they ignored the sentence that followed closely behind. It read, “Most of this quantity is contained in prepared foods.”
Indeed, from the references of your link:
The Panel has decided that the reference values for total water intake should include water from drinking water, beverages of all kind, and from food moisture.
> This is way WAY too much water, especially if you're drinking anything on top of it. Shoot for 2.5 to 3.5 liters a day maximum. If you do this for any prolonged period of time, or multiple weeks in a row, you're going to have issues.
Source? Or what kind of issues? I average 5~8 l on a normal day and have been for years. The few times I've had my values checked they were mostly fine, apart from the lab being hassled by the huge sample they got for my 24h urine. Naturally I have a bit higher salt intake than most.
Except it's well known that that is way too much water unless you are sweating a lot. If you drink that much, you'll just pee a lot, it won't actually do anything useful.
Since the article got something so basic wrong (and if it was intentional you would think they would mention that the numbers were similar), I decided to stop reading the article at that point, I don't need incorrect information.
Maybe it's an editing mistake?
The actual amount of water you need varies by exertion, and diet and all sorts of things, it's not a fixed amount.
In 1945 there was a recommendation that a healthy adult should have about 2.5 liters of water intake a day, including water that is part of the food you eat.
Somehow the media managed to drop the last part, and recommended you drink at least 2l water a day. Or even more.
This article seems rife with BS.. Not going to bother going into detail. But one example: you need to drink 3.2 L of water a day, is completely baseless as far as I'm aware.
I dont want to doubt you but from my own experience that seems insane. Is there a medical/enviromental reason for? Do you take salt tablets as well?
I drink a single glass of water in the morning, 200ml and I have a .7L glass bottle because I dislike the way plastic tastes. But thats a hard maximum that I could tolerate drinking.
I've also had blood tests done that do not show any dehydration in the slightest so I'm just curious why/how anyone could drink that much water without poisoning themselves.
> Drinking around 1 liter of water for each 30kg of body weight per day
I don't think there is any scientific basis for drinking water when you're not thirsty. I suspect this idea originated from marketing for bottled water.
This is a myth. You're supposed to have around 2 l of water, from all sources: meaning that you'd have to eat only freeze-dried food to actually need that much water.
Ok, but that’s an extreme example and you only consumed 3.8L. 4.5L is a LOT. Even the 8 glasses a day of water suggestion is considered on the high side and that’s only 1.9L.
>The actual amount of water you need varies by exertion, and diet and all sorts of things, it's not a fixed amount.
I completely agree with this statement.
>If you drink that much, you'll just pee a lot, it won't actually do anything useful.
I drink on average 6L of water a day. When I first started water-only fasting I was urinating constantly. I discovered that this was because I would drink a lot in one sitting, (as a 'meal' replica) and then interspersed throughout the day.
Once I changed my consumption style to ~150mL frequently I found that my body used the water better. Once it realized that a "constant supply" was readily available (and didn't need to worry about feast/famine cycles) I retained what I needed and more casually urinated the processed water.
My body can better manage itself when I drink 150ml 40x a day then it can manage 1L 6x a day.
> are just drinking more often but smaller amounts?
Probably. I don't measure my water consumption, but I'm guessing that I drink smaller amounts. Even if my average hydration level is the same, it never goes too low this way, which means that I feel better.
I don't have any objective way to measure the health benefits of drinking a certain amount of water, but it definitely makes me feel better to be more hydrated, so I'm guessing it's good for my health.
Did you read his article and looked at what you're referencing?
From the website you're referencing:
> Adequate Intakes (AI) have been defined derived from a combination of observed intakes in population groups with desirable osmolarity values of urine and desirable water volumes per energy unit consumed.
The article attacks exactly that line of reasoning:
> I’m a pediatrician, and I can tell you that I have rarely, if ever, used urine osmolality as the means by which I decide if a child is dehydrated. When I asked colleagues, none thought 800 mOsm/kg was the value at which they’d be concerned.
More importantly, intake of water != drinking water.
95% of lettuce is water, on the extreme end, but it's not unique. 90% holds for carrots or beets, too. For potatoes it's about 70 to 80%. And when cooked, it soaks up even more water. That adds up quickly and severely reduces the amount of glasses of water you actually need to drink. After all, 2.5 litres of water would easily amount to (over) 8 cups/glasses of water. The article attacks exactly that notion.
Kidney specialists do agree on one thing, however: that the 8-by-8 rule is a gross overestimate of any required minimum.
"The notion that there is widespread dehydration has no basis in medical fact," says Dr. Robert Alpern, dean of the medical school at the University of Texas Southwestern Medical Center in Dallas. Doctors from a wide range of specialties agree: By all evidence, we are a well-hydrated nation. Furthermore, they say, the current infatuation with water as an all-purpose health potion — tonic for the skin, key to weight loss — is a blend of fashion and fiction and very little science.
From an LA Times reader:
The advice fully meets three important criteria for being an American health urban legend: excess, public virtue, and the search for a cheap "magic bullet."
> quite a few people don't actually hydrate enough during the course of a day
Do you have some cites for this? I've heard some of the dumbest damn things about water (like the 'eight glasses a day' myth) and it's hard to keep them all straight.
The recommended amount depends on who does the recommendation but 1.9L doesn't seem high.
https://www.efsa.europa.eu/fr/efsajournal/pub/1459
"Adequate Intakes (AI) have been defined derived from a combination of observed intakes in population groups with desirable osmolarity values of urine and desirable water volumes per energy unit consumed. The reference values for total water intake include water from drinking water, beverages of all kind, and from food moisture and only apply to conditions of moderate environmental temperature and moderate physical activity levels (PAL 1.6). [...] Available data for adults permit the definition of AIs as 2.0 L/day (P 95 3.1 L) for females and 2.5 L/day (P95 4.0 L) for males."
https://apps.who.int/iris/handle/10665/43403
"The minimum water requirement for fluid replacement for a 70kg human in a temperate zone equates to 3L per day, or 42.9mL/kg [according to the Tropical Agriculture Association]. Minimum requirements for an individual the same size but in a tropical zone equates to 4.1 to 6L/day"
"Age and gender specific Adequate Intakes (AI) for water were established in 2004 by the [United States] Food and Nutrition Board (5). The Dietary Reference Intakes (DRI) for water are [for ages 19 and older] Men 3.7 L/day Women 2.7 L/day"
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