Coffee, co*cktails, and 5 More Drinks That Are More Dehydrating Than You Might Think (2024)

Hydration looks different for everyone. Some carry around a massive tumbler of water, others keep it on a daily subconscious to-do list, and then some people will go about their business only to realize upon returning home from work that they haven’t had a sip of water all day. No matter where you fall on that spectrum, hydration is always important—and it becomes an even higher priority as the hot months of summer approach.

While we all know water is the ultimate hydrator, are there any drinks that actually contribute to dehydration? Here are some of the most popular beverages that can have a negative impact on hydration, plus how to help offset their dehydrating effects—especially in the heat of summer.

Avoiding Dehydration Is Very Important

Proper hydration positively supports our bodies in myriad ways, especially given that we’re composed mostly of water (at least 60%). These hydration benefits range from optimal brain, joint, immune system, kidney, liver, and gut health to aiding the body in detoxification, metabolism, and nutrient absorption. Plus, proper hydration helps to protect the skin, spine, eyes, nose, and mouth from irritants and stressors.

While we always want to avoid dehydration as best we can, it’s especially paramount as the temperature rises, leaving us more susceptible to dehydration. A few of the main, everyday ways we can lose moisture and become dehydrated (if we’re not replenishing that moisture) include breathing (who knew?), going to the bathroom, and sweating. These are our body’s natural excretory systems. In the summer months, many of us sweat far more than other times of the year, predisposing us to the irritating symptoms of dehydration.

For most of us, dehydration can present as lightheadedness, headache, decreased cognition, insomnia, fatigue, unusual mood swings, gas, bloating, constipation, dark-colored urine, and less frequent urination.

When dehydration becomes super severe, it can have much more serious medical consequences including cardiac events, seizures, and organ failure. This level of dehydration typically only occurs as a result of extreme circ*mstances like severe illness or prolonged, strenuous exercise without proper fluid replacement. However, the intense heat of summer can cause some of us to lose enough fluids to go into heat exhaustion potentially leading to some of these symptoms if not properly attended to.

Avoiding dehydration is simple in concept: drink (and eat) more fluids than your body is losing throughout the day. However, in practice, it is much more difficult, as many of us know. When we feel thirsty we’re actually already behind on hydration, and many Americans live with chronic low levels of dehydration. But the key to success here is to make small attainable goals towards a larger one – which would be aiming for at least eight to 12 cups of water (64 to 96 fluid ounces) or other hydrating beverages per day. (Remember, too, that many foods, including fresh fruits and veggies, help contribute to hydration levels throughout the day.)

What Makes a Beverage Dehydrating?

Not all drinks are as hydrating as they may seem. You might think that because something is a fluid that it’s inherently hydrating, but this is not always the case. In fact, many of the bevs we love in this country are actually pretty dehydrating, at least to some degree. When speaking of dehydrating drink components, the diuretic effect is a concept at play with each one. Diuretics are agents that cause the body to produce and pass more urine than it otherwise would, having the potential to dehydrate us.

A few dietary components, each of which has diuretic effects, can contribute to dehydration, including the following:

Added Sugars

Added sugar causes the kidneys to excrete more fluid. Plus, when we consume large amounts of added sugars, there will be a build up of sugar in the bloodstream after the cells take what they need to function. When substances like salt and sugar are more concentrated in the blood than in the cells, the body will pull water from the cells into the blood to try and create an equilibrium between the two structures in terms of water and solute (i.e. salt or sugar) concentration. No matter, when water is pulled from our cells to dilute the sugar concentration in our blood, that will result in dehydrating effects throughout the body.

Excessive Amounts of Caffeine (More Than 500 Milligrams)

This stimulant is also a classic diuretic that many people are already aware of. However, the amount you consume here is key. One 2017 study published in Frontiers in Nutrition found that only caffeine consumption over 500 milligrams (mg) was associated with diuretic effects. Given that an 8-ounce cup of coffee can contain anywhere from 80 to 100 mg of caffeine, according to the FDA, many coffee drinkers may not approach this threshold. However, other options like energy drinks can have double or more of that amount, increasing the risk of diuresis and dehydration associated with a lot of caffeine.

Alcoholic Drinks

On the other side of the coin we have the most frequently consumed depressant: alcohol. Alcohol acts as a diuretic in a few different ways, and is well-known for being very dehydrating—one of the biggest reasons it leaves most of us with hangover symptoms.

Alcohol is processed by the liver, which produces acetaldehyde and other byproducts when metabolizing co*cktails. While many of these will be removed from the body through carbon dioxide and water release from the lungs (i.e. this is how breathalyzers work) some will be metabolized and excreted through the kidneys. Alcohol also suppresses the antidiuretic hormone vasopressin, exacerbating this beverage's diuretic effect and dehydration capacity.

Certain Artificial Sweeteners

While not all artificial sweeteners are equally offensive to hydration levels, some can really contribute to dehydration, mainly through their impact on digestion. Added sugar alcohols like sorbitol, xylitol, erythritol, and mannitol are especially notorious for producing a laxative effect resulting in diarrhea, which can cause dehydration. This is likely due to their capacity to alter gut bacteria in the microbiome.

Very High Amounts of Protein

Though harder to come by in drinks when compared to food, high protein intake (a health trend in and of itself these days) can also result in dehydration. This macronutrient breaks down into nitrogen during digestion, which requires more water to metabolize, pulling from our body’s stores. Plus, the kidneys are charged with excreting this excess nitrogen, resulting in diuresis and, of course, the potential to dehydrate.

Common Drinks That Can Dehydrate You

So, with our science lesson for the day out of the way, let’s get into some of the most dehydrating beverages available so that you can make the best choices for your overall hydration this summer.

While you don’t necessarily need to avoid dehydrating drinks—they’re a delicious part of life and hard to pass up—it’s good to know which are the worst culprits so you can make the most informed decisions for good hydration. This can help you to stay healthy and energized during the hottest summer months, when dehydration is a real concern.

How to Enjoy Your Favorite Beverages and Stay Hydrated

So how can you best manage and potentially offset dehydration—without missing out on the joys of lemonade, mojitos, and iced coffee?

If hydration is your number-one priority, avoiding or significantly reducing consumption of these drinks is probably your best bet. But another option would be to get creative and make alternatives for these classic beverages at home. This could look like choosing decaffeinated coffee and tea drinks, lower-protein smoothies, infused waters instead of sugary juices, lemonade, or sodas, or fresh juices full of hydrators like watermelon, citrus, and cucumber.

Another route? For every less-hydrating drink you have, alternate with one hydrating choice (read: a glass of water!). Bored of water? Try infused water with cucumber or citrus, flavored seltzer waters, low-sugar juices or kombucha, or decaffeinated coffee or tea.