10 foods to keep you hydrated on hot summer days

By Naveed Saleh, MD, MS, for MDLinx
Published July 11, 2019

Key Takeaways

Think that all your hydration comes from drinking? Think again. About 20% of our fluid intake comes from the foods we eat. But, not all foods contribute to your hydration status. Some—those high in protein, fiber, and salt, for example—end up doing the opposite; they deplete your fluid reserves.

Especially on hot summer days, it’s important to keep hydrated. In addition to drinking the recommended 6-8 glasses of water daily, here are 10 foods you can turn to that’ll help do the trick.


These fruits are made up of 74% water. In addition, they contain potassium, an electrolyte that is depleted during dehydration. Electrolytes, like potassium, are responsible for a great many functions. For example, they help our bodies produce energy, and even enable our muscles—like the heart—to contract. Electrolyte imbalances can cause serious problems, and can be caused by things as simple as not drinking enough. It’s no wonder that bananas, along with their travel-friendly design, are a darling food of exercisers the world over.


Considering how texturally hard it is, you may be surprised to learn that cauliflower is a hydrating vegetable. In fact, cauliflower is 92% water by weight. It also contains loads of vitamin C, vitamin K, and other key nutrients. Cruciferous veggies like cauliflower have been tied to cholesterol improvement and reduced cancer risk. To make cauliflower more palatable, try boiling it first.


Celery is 95% water by weight, which makes it a very low-calorie food. In addition to lots of water, celery also contains key nutrients, such as vitamin K, folate, and potassium. Furthermore, celery will give you a crunch that can serve as a cravings substitute for chips and crackers.


A cucumber’s composition includes 96% water. Researchers from the University of Aberdeen, Aberdeen, Scotland, have shown that, after a workout, cucumbers can deliver the same hydration levels as twice the same volume of water. Cucumbers’ extra punch is due to their electrolyte content, which helps the body retain water. Moreover, if you peel the skin, you can get even more water into your system.


Popeye ate spinach to increase his strength, but he could just as well have consumed it for its ability to hydrate. Spinach is 92% water. Pound for pound, it is also the richest dietary source for magnesium, which is an electrolyte.

Iceberg lettuce

Although not as nutritious as dark leafy greens like spinach, iceberg lettuce is much higher in water content. Iceberg lettuce is made up of 96% water, with the rest mostly fiber. The fiber content may reverse some of iceberg lettuce’s hydration properties, but iceberg lettuce is still an excellent source of fluids. Just don’t drown your lettuce in high-calorie salad dressing—a fluid that won’t hydrate you to say the least.


Radishes rival iceberg lettuce in water content—weighing in at 95% water. Eating peeled radishes increases their water content even more by doing away with fiber.


Strawberries are comprised of 91% water, and are chockfull of flavonoids—antioxidants linked to enhanced brain function. In one study, consuming berries delayed cognitive aging for more than 2 years. To increase the hydration effect of strawberries, try pureeing them.


Watermelon is the quintessential summer fruit, and for good reason: it contains 91% water. It is also a rich source of lycopene, which offers protection from the sun. Although sweet, watermelon is only 8% sugar. It is also rich in the electrolytes sodium, magnesium, and potassium.


The fictional Ron Burgundy once exclaimed “milk was a bad choice” on a hot summer day. But guess what? According to researchers from McMaster University, Hamilton, ON, Canada, milk hydrates you better than sports drinks due to its combination of sugars, protein, calcium, and electrolytes.

On a final note, there are plenty of other hydrating food sources that you can easily find at your local grocery store or farmers market—including cantaloupe, oranges, and zucchini. To boot, more unexpected hydrating options include some soups and broths, as well as cottage cheese and yogurt.

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