This Is What Happens to Your Body If You Drink 3 Gallons of Water a Day

I know because I tried it.
Glass of water on wooden table
Rialto Images / Stocksy

Drinking plenty of water has been shown to have several benefits including increased physical performance, higher energy levels and brain function, and the regulation of body temperature. If you're backed up, drinking water should be the first item in your action plan for pooping. It’s been shown to rev up metabolism and help you to consume fewer calories (if that's one of your goals). Being adequately hydrated is also useful in preventing headaches and—if you have the wherewithal to drink a glass of water between alcoholic beverages on a night out, you're reducing the risk and severity of both a hangover and—as I’ve previously discussed—shitting your brains out the following day. There’s even evidence that being optimally hydrated is linked to better erections, so it's easy to understand why people are constantly reminding themselves and each other to drink more of the stuff.


YouTube is full of people doing the self-imposed One Gallon Per Day challenge, so I decided to up the ante and see if more water equated to more benefits. I chose three gallons per day because this was the volume Hugh Jackman sank in preparation for getting shirtless in the Wolverine movies. The point of that, as I've discussed in a previous article, is to load the body with water, causing it to work like hell to get rid of it all. Then you cut off your water intake completely for the last 24 or 36 hours before an event before your body figures out what's going on and, voila, temporary six-pack.

Now I may not possess the looks, pipes, or moves of the man hogging all of Australia's talent, but there's no reason to believe that my kidneys aren't a match for his. Regulating the amount of water in the body and balancing the concentration of minerals in the blood is the kidneys' main function. But while there’s a link between drinking water and being three-quarters of an EGOT winner, there’s a less-talked-about dark side to it: It can be deadly. When I decided to drink 384 fluid ounces every day for a week just to see what would happen, I knew I’d have to avoid hyponatremia in the process.

“Hyponatremia occurs when consuming too much water dilutes the sodium in the blood,” says New York City-based registered dietician Amy Shapiro. As an electrolyte, sodium helps regulate the amount of water that’s in and around your cells. When sodium is low, she tells me, your cells become waterlogged and begin to swell. Symptoms of hyponatremia can range from nausea, vomiting, and confusion to seizures, coma, and death. It’s often seen in endurance athletes who sweat out vast amounts of sodium that they don't replace (that is, by consuming enough electrolytes).


When I tell Shapiro, she tells me something that seems to square with what you're probably thinking. "For most people, three gallons of water is too much to consume in one day," she says. The person's weight, activity level, and the climate their living in play a significant role in determining how much water they need or can tolerate.

It's also prevalent among MDMA users. The first ecstasy death that led to a full-blown moral panic in the UK was that of an 18-year-old named Leah Betts in 1995. While a "bad batch" of the drug was blamed for her coma and death five days later, hyponatremia was found to be the actual cause. Betts consumed seven liters of water—around 1.85 gallons—in 90 minutes. Paradoxically, she was tripling down on the advice given to ravers to drink more during and after dancing for hours on end.

I knew that to meet my goal without any of the side effects (up to and including death), I'd have to spread my water intake evenly throughout the day. My previous experience of drinking large volumes of water taught me that even with the assistance of an app, like Waterlogged or Hydro Coach, it’s easy to fall behind. Playing catch-up to get to two gallons had been a nightmare—falling behind and then trying to get to three could even be dangerous. "If you do choose to drink this much throughout the day, I would recommend spacing it out and being sure you are getting enough sodium and potassium through your diet so you do not flush out your electrolytes which could lead to a heart attack," says Shapiro.


Given that I'm awake for roughly 16 hours per day, I divided the 384 ounces in three gallons of water by 16, which meant that with every hourly notification, I'd have to drink 24 ounces of water. That's a fortuitous volume for three reasons. Twenty-four ounces is the capacity of my trusty water bottle, it's far less than the average capacity of a stomach (which can expand to hold up to four liters), and it's a little below the 27 to 33 ounces of water that a pair of healthy kidneys can excrete per hour.

On Day One, I woke up, as I often do, in a fairly hazy state. I then made, as I always do, for the coffee pot. I'd drunk an admittedly insane four cups and whiled away an hour watching the previous evening's late show monologues before I remembered the task at hand. If I was going to stay on target, I’d need to get 48 ounces of water down my throat stat—this on top of 32 ounces of piping hot French roast.

Somehow, I didn't puke, but I spent the rest of the morning feeling awful, broken up with bouts of pissing like a racehorse multiple times per hour. Breakfast on top of the deluge was simply out of the question, but around 2 PM I had the novel sensation of feeling both hungry and full to the gunnels. I managed to choke down a heavily salted vegetable stir fry but generally felt like ten pounds of sausage in a five-pound bag and didn't leave my apartment all day.

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I made a concerted effort to pee out the last of the water before I went to bed yet got up three times before dawn. When the morning of Day Two finally rolled around, I saw the sticky note reminder I’d stuck to the back of my bedroom door and began saturating myself in earnest. I made a full French press of coffee but could only drink a cup before registering slight nausea once again. (On the plus side, that coffee begat an awesome poop that was so massive I was tempted to take a picture of it as a sports fisherman might pose with a prize marlin.) And, aside from the first bathroom trip in the morning, the liquid I was evacuating was just about as clear as the liquid I was imbibing—nearly clear pee indicates that you're well hydrated.


From that point on, my schedule dictated that I leave my apartment several times a day. Leaving meant drinking my hourly allotment, peeing out as much of it as I could, then praying that I could get to where I was going before I wet myself. This boiled down to checking, then double checking subway service alerts and relinquishing any qualms I had about asking to use the bathroom of an establishment of which I am not a patron.

Two minutes before arriving at friends' apartments, I got into the habit of calling them to ensure that their bathroom was ready for my immediate use. This sort of malarkey meant that I had to 86 any non-essential obligations I had in order to be a few steps away from a toilet. The one exception was the gym. Provided I could get there without an accident, sweating became another way of getting rid of some liquid. In a previous Tonic article, I’d discovered that I sweat out around a liter per hour.

As the week wore on, I did find myself feeling more alert and energetic. I was always a regular guy, but my stools seemed more substantial and left me with a euphoric—or poo-phoric—feeling almost every time. As research has shown, drinking plenty of water is a surefire way to consume fewer calories and, as the week drew on, I'd started to look more svelte and even got my nocturnal pissings down to one per night.

Friends who I hadn't told about the experiment said that I seemed brighter-eyed and more rested, which was a nice endorsement. As the week drew to a close, I started to get thirsty in between bottles. It was as though the act of pushing 25 pounds of water through my body each day had somehow recalibrated it.

After I’d excreted all the water I’d put in on Day Seven, I discovered I’d lost six pounds in addition to looking, feeling, and pooping better. All good stuff, but not nearly enough of an incentive to incur the overhead of thinking through my day as much I had to. In the week or so following my experiment, I’ve found that drinking a considerable but much smaller amount of water per day would be enough to realize the benefits of being hydrated at all times without experiencing the drawbacks.

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