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What Happens to Your Body When You Drink a Gallon of Water Every Day

Is drinking a gallon of water per day too much? Here’s what dietitians think.
FACT CHECKED BY Olivia Tarantino

It goes without saying that drinking water and staying hydrated are integral to your body's ability to function and remain healthy over time. Whether you're highly active; live in a warm, arid, or humid area; or you've just had a fair share of regrettable hangovers, you've probably walked the dehydration line more times than you'd like to admit. That also means you'd be familiar with the uncomfortable consequences that can accompany this condition—nausea, headache, lightheadedness, exhaustion, and dry mouth, to name a few. Remembering to sip on H2O consistently throughout the day is an easy way to avoid this miserable fate, but is it possible to drink too much water daily? For instance, what might happen to your body if you were to drink a gallon of water each day?

How much water should you have in a day?

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Before diving into the potential advantages and consequences of drinking at least a gallon of water daily, it's important to note the recommendation for daily water consumption to recognize how much might be too much for you.

"Typically, men need about 15.5 cups of fluid a day (3.7 liters, nearly a gallon), and women need about 11.5 cups of fluid (2.7 liters, nearly three-fourths gallon)," the Nutrition Twins, Lyssie Lakatos, RDN, CDN, CFT, and Tammy Lakatos Shames, RDN, CDN, CFT, tell Eat This, Not That! "This includes all fluids from water, other beverages, and food. Typically, about 20% of the daily fluid intake comes from food and drinks, aside from water."

At the same time, these are just general suggestions. Truthfully, everyone's daily water limit will ultimately differ based on a few key factors personal to the individual.

"The amount of water you need to drink over the course of the day is affected by your gender, age, weight, what your diet is comprised of, and how active you are—which can cause needs to vary a good deal," the Nutrition Twins explain.

With that in mind, it's hard to say how drinking a gallon of water (aka 4.5 liters) each day will wash out for you personally, in terms of the possible benefits and side effects that could arise. And although last year's viral TikTok Water Gallon Challenge trend may have motivated you to up the ante on your regular hydration habits or inspired your curiosity about the effects of drinking more water, you should consult your healthcare provider to find out precisely how much water is best suited to fulfill your unique needs before you start hastily chugging away.

Assuming your physician says it's safe for you to make drinking a gallon of water daily part of your routine, here are some possible effects to look out for the more you continue drinking water at this volume on the regular. And for more advice to help support healthy hydration, be sure to check out What Happens to Your Body When You Drink Lemon Water.

You may lose weight.

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According to the Nutrition Twins, once you start drinking at least a gallon of water daily, you may start to realize that your appetite isn't as strong as it once was. This is because sometimes our brains can cross signals in a way that causes us to mistake thirst for hunger. When your body is inadequately hydrated, it's possible that your go-to instinct to satisfy this craving might be to eat more food instead of opting for the H2O your body actually seeks. As a result, you may end up consuming extra food and calories.

Conversely, guzzling a gallon of water each day can help repress your urge to overeat and manage your cravings, enabling you to react accordingly when you genuinely feel thirsty versus hungry. This can then, in turn, result in weight loss.

"When you drink more and are properly hydrated, that hunger no longer exists, and you can shed pounds as you stop consuming extra calories that were a result of dehydration," says the Nutrition Twins.

You may lose touch with your sense of hunger and satiety.

On the flipside, regularly drinking a gallon of water a day might also potentially blur your organic body cues and intuition when it comes to experiencing a genuine sense of fullness, even after eating a reasonably portioned meal.

"While drinking plenty of water can help you to prevent mistaking thirst for hunger," the Nutrition Twins warn, "if you're drinking a lot of water in an attempt to squash hunger for weight loss, and you're constantly causing your stomach to feel distended, you may stretch your stomach and adjust to this feeling—and it will require more food to feel full."

In other words, drinking a gallon of water a day does not give you the license to go off the rails with your other healthy dietary habits. Though resisting the urge to overeat can be challenging, maintaining a healthy awareness of your eating habits relative to your new drinking routine will be beneficial to your overall health.

You may spend a lot of time running to the bathroom.

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"Drinking a gallon of water each day may help mitigate constipation in addition to any related symptoms," say the Twins. However, daily consumption of this much water could also lead to more frequent urination.

"When you drink too much, it can't all just stay in your body—it has to make its way out. So, frequent bathroom trips are to be expected," they say.

So, unless you like spending most of your day searching for an available restroom, you might want to be mindful of when and where you decide to drink water and avoid overdoing it beyond the recommended quantities. Besides, do you really want to keep waking up in the middle of the night to scoot to the loo, or be that person on road trips who must stop every few minutes to find a bathroom? I don't think so.

It may make you aware that you need more electrolytes.

According to the Nutrition Twins, drinking a gallon of water every day may make it easier to recognize when you're experiencing an electrolyte deficiency or that you need to add "a pinch of Celtic salt to your water."

"If you're drinking a lot of water and continue running to the bathroom when you don't drink it with meals, it could mean that you don't have enough electrolytes to absorb the water," say the Twins. "So, it's running right through you—literally."

"Add electrolytes or a pinch of Celtic salt to your water and see if your trips to the bathroom decrease," the Twins suggest.

You may become more regular—and less bloated, too.

If you've ever had constipation troubles, there are a few foods or beverages out there that can help you get things moving again at a healthy flow rate. However, another simple solution to overcoming that backed-up, bloated feeling so you can poop to your body's content is to simply drink more water.

"Many people struggle with constipation and the bloat that comes with it simply because they don't drink enough water. So their stool ends up being hard and difficult to pass," says the Nutrition Twins. "If you aren't getting enough water and increase your consumption as you strive to drink a gallon of water, you'll help to make the stool softer and easier to pass. And as you become more regular, the bloat that came with constipation will be relieved too."

RELATED: 8 Drinks To Help You Poop Immediately

You may look younger.

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Evidently, any water fountain can essentially function as a mini Fountain of Youth. According to the Nutrition Twins, water carries nutrients to the skin that helps hydrate while simultaneously filling the spaces between cells.

"This helps to prevent dehydrated skin that can look sunken and weathered," they say. "Staying hydrated also plumps up the cells making skin look more youthful."

You may have more energy.

Who needs the caffeine from coffee or energy drinks when you have the natural wonders of water helping you throughout the day? The Nutrition Twins claim that a gallon of water can even keep you refueled and recharged all day long.

"Water carries nutrients and oxygen throughout the body to the brain and to working muscles. If you're even slightly dehydrated, you feel tired because oxygen flow to the brain is impaired. What's more, your heart then must work harder to pump oxygen to your organs and throughout your body, which is tiresome," the Nutrition Twins explain. "In fact, research has found that just 1.6% of dehydration causes fatigue. This is considered just mild dehydration, which is 1–3% of body weight, [or] 1.5–4.5 pounds in a 150-pound person."

You may have more difficulty digesting your food.

While proper hydration is essential to maintaining your overall health, those with digestive issues might want to think twice before drinking this much water daily.

"Although this likely only will be the case for some people who have digestive issues, drinking large amounts of water with meals is not a good idea as it dilutes digestive enzymes, and these people may have more issues digesting their food," the Nutrition Twins advise.

You may experience nausea, fatigue, confusion, or headaches.

Nausea and Fatigue
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Do these symptoms sound familiar? Perhaps you felt similar symptoms when a bit dehydrated. Interestingly enough, you're also at risk of experiencing nausea, fatigue, confusion, and headaches when you have too much water. If you go overboard with how much water you consume each day, you can increase your chances of developing other serious health issues.

"When you get too much water, it dilutes the sodium in your body, which can lead to hyponatremia," says the Nutrition Twins. "This can put you at risk for seizures, going into a coma, or even dying."

You may prevent urinary tract infections.

For those who tend to be susceptible to urinary tract infections (UTIs), chugging tons of cranberry juice isn't the only beverage-related tactic to help to avert discomfort. According to the Nutrition Twins, drinking lots of water can be a UTI deterrent.

"Water not only dilutes your urine, but it means that you'll be urinating more frequently, which flushes bacteria away from the urinary tract, preventing infections," says the Nutrition Twins. "One study showed the women who drank 1.5 liters of water daily had a 50% reduction in recurrent cystitis, a type of urinary tract infection."

You may prevent kidney stones.

Kidney stones are painful, hard mineral deposits that can develop in your kidneys. This pain only further intensifies when your body attempts to "pass" them, expelling them via your urinary tract. However, the Nutrition Twins assert that water can help minimize your chances of possibly developing kidney stones.

"One of the best ways to prevent kidney stones is by drinking plenty of water to prevent the stone-forming crystals from sticking together," says the Nutrition Twins. "Research has shown that for every 0.5-liter water increase, you can significantly reduce stone formation."

You may have less joint pain.

While there are foods and drinks that can make joint pain worse, there are also things you can consume that may aid in alleviating these aches and keeping your joints healthy. Drinking water and staying hydrated is one recommended strategy that the Nutrition Twins claim can help your joints feel loose and limber.

"Being properly hydrated lubricates the joints, so you may move more easily and feel less pain and stiffness," say the Nutrition Twins.

A previous version of this story was published on October 13, 2022. It has been updated to include additional copy and proofreading revisions, additional research, and updated contextual links.

Jordan Powers Willard
Jordan Powers Willard is a Deputy Editor for Eat This, Not That! Read more about Jordan
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