Stay Hydrated, My Friends takes a look at all things hydration, dehydration and the different ways to meet your daily water needs.
You already know just how important it is to stay hydrated by drinking plenty of water.
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Hydration regulates body temperature, prevents infections, helps organs function properly and keeps joints lubricated, per the Harvard T.H. Chan School of Public Health. Staying well-hydrated also benefits your mood, brain function and sleep quality.
That said, water isn't the only way to hydrate! Your favorite fresh foods can also significantly contribute to your daily water intake.
"We meet 20 percent of our hydration needs from food," says Dawn Jackson Blatner, RDN, CSSD. "Food allows us to hydrate with variety and it offers a lot of nutrition if you're picking the right high-water foods."
Fresh produce typically provides the most water content — and this is particularly true of vegetables. That said, you can also hydrate with foods made with water, such as soaked lentils, soup or even whole-wheat pasta.
"Having foods that contain a lot of water will help you feel more full than dry foods," Blatner says. "They have more volume, so they push on your stomach wall to signal to your brain that you're satiated."
Here are the most water-rich foods you can put on your plate to stay hydrated.
1. Iceberg Lettuce
96 percent water
Although it doesn't have the same star status as many other leafy greens, iceberg lettuce is packed with water and other nutritional benefits.
One cup of iceberg lettuce provides 14 percent of the daily value (DV) of vitamin K, which is important for healthy bones, blood clotting and other functions in the body, per the National Institutes of Health (NIH). Some research has observed that people who eat vitamin K-rich foods have stronger bones and are less likely to break a hip than people who eat less of those foods.
"Vegetables like iceberg lettuce, which may not have as much of a buzz as kale or cauliflower, still absolutely provide hydration, vitamins and minerals," Blatner says. "Plus, eating a variety of leafy greens for diet diversity is important, because every fruit and vegetable provides different beneficial compounds."
Iceberg lettuce also contains a range of B vitamins, including folate (B9), vitamin B6, pantothenic acid (B5), thiamin (B1), riboflavin (B2) and niacin (B3), per the USDA.
95 percent water
This vegetable is a great pick for staying hydrated and satiated for very few calories. With just 11 calories, two medium stalks of celery provide 20 percent of the DV of vitamin K, plus potassium, B vitamins and other essential vitamins and minerals.
"Celery is like nature's sports drink because it naturally contains electrolytes lost in sweat such as sodium, potassium, magnesium and calcium," Blatner says.
What's more, this vegetable can benefit your teeth. Because of its fibrous texture, chewing celery can help clean your teeth and generate saliva that neutralizes acid left behind from food in your mouth, per the University of Illinois at Chicago College of Dentistry.
It's also a good source of beta-carotene, which the body needs to create vitamin A, which is necessary for building strong teeth.
3. Bok Choy
95 percent water
One cup of bok choy contains 35 percent of the DV of vitamin C and is also a great source of vitamins A and K. Like many of the other foods on this list, bok choy is low in calories, with just 9 calories per cup.
"It's in the same superfood family as broccoli and kale, so it's a superstar of nutrition," Blatner says. "In addition to antioxidant vitamins A and C, it contains bone-building calcium and magnesium and blood-building vitamin K and iron."
Many studies have found that cruciferous vegetables like bok choy are associated with a lower risk of certain cancers, particularly lung, colon and prostate cancers, according to the Tufts University Friedman School of Nutrition.
95 percent water
They're delicious topped on a hydrating summer salad, but radishes also provide plenty of water on their own and are rich in antioxidants.
"Radishes contain a healthy compound called anthocyanin, which may help with heart health and is linked to a reduced risk of diabetes," Blatner says. Anthocyanins are the same beneficial compounds found in blueberries and strawberries.
A half-cup of sliced radishes has just 9 calories but provides 10 percent of the DV of vitamin C, as well as potassium, copper and manganese.
95 percent water
Just one cucumber provides plenty of water, along with vitamins, minerals and even some protein! In particular, cucumbers are an excellent source of bone-healthy vitamin K, with 41 percent of the DV.
"Cucumbers also provide vitamin C, which is required for collagen synthesis and helps with wound healing," says Erin McNamara, RDN. "This vitamin also helps your body absorb plant-based iron foods." One cucumber provides 9 percent of the DV of vitamin C and 5 percent of the DV of iron.
Plus, cucumbers contain potassium, which is necessary for crucial body processes like proper kidney and heart function, according to the NIH. They also provide phosphorus, which plays an important role in the body's use of carbohydrates and fats, and in the formation of bones and teeth, per the U.S. National Library of Medicine.
95 percent water
An entire cup of watercress contains just 4 calories, but 71 percent of the DV of vitamin K and 16 percent of the DV of vitamin C.
"Watercress is one of the highest antioxidant foods around," Blatner says. In fact, 14 phenolic compounds — plant compounds with antioxidant properties — were identified in watercress leaves in a November 2015 study published in the journal Springerplus.
95 percent water
Like cucumbers, zucchinis contain vitamins K and C, potassium and phosphorus. One medium zucchini provides nearly 40 percent of the DV of vitamin C.
"Zucchinis also provide fiber, which all fruits and vegetables have in varying amounts — and which helps you feel full," McNamara says. One medium zucchini provides 2 grams of fiber, or 8 percent of the DV.
Dietary fiber passes through your digestive system to help normalize bowel movements, lower cholesterol levels and control blood sugar levels. Foods with fiber, such as zucchinis, tend to take longer to eat and be lower in calories for the same volume as other types of food, and can help you achieve a healthy weight, according to the Mayo Clinic.
As with other vegetables, opt for fresh zucchini if you want to hydrate. "Cooking methods like roasting reduces water content, so it's best to have vegetables raw if you want to get the full hydration benefits," McNamara says.
95 percent water
Fresh, juicy tomatoes are packed with water. One medium tomato contains 34 percent of the DV of vitamin A (IU), which is important for normal vision, the immune system and proper function of the heart, lungs, kidneys and other organs, per the NIH.
It also provides 19 percent of the DV of vitamin C and 6 percent of the DV of potassium.
"People often don't realize tomatoes are so high in water," McNamara says. "They also contain lycopene, an antioxidant that helps prevent cell damage."
Diets that contain fruits and vegetables high in carotenoids (plant compounds) like lycopene are tied to preventing some types of cancers and heart problems, per the Memorial Sloan Kettering Cancer Center. But stick to fresh and cooked tomato foods: There isn't sufficient research to determine if lycopene supplements have the same effect.
9. Green Bell Peppers
94 percent water
You'll also get 16 percent of the DV of vitamin B6, which is needed for more than 100 enzyme reactions that play a role in metabolism, per the NIH.
It's worth including a variety of peppers in your diet to stay hydrated, such as green bell peppers, red bell peppers (which have even more vitamin C) and even hot peppers. "Spicy foods like hot peppers will stimulate thirst, which can also help keep you hydrated," Blatner says.
91 percent water
Although there are other foods with a higher water content than watermelon, this juicy fruit deserves special mention here. Watermelon provides not only plenty of water, but it's also a food that provides electrolytes that can help replenish your body after sweating — especially if you salt your slice.
"Sprinkling a pinch of salt on watermelon brings out its sweetness, and it's almost like making your own edible sports drink," Blatner says. "It'll help replenish sodium, one of the main electrolytes we lose through sweat."
Like many other types of produce, one cup of watermelon also provides electrolytes such as potassium and magnesium.
Electrolytes regulate muscle contractions, keep you hydrated, balance your pH levels and control nervous system function, per Cedars-Sinai. Low electrolyte levels can cause fatigue, nausea, headache, blood pressure changes and muscle cramps.
- Harvard T.H. Chan School of Public Health: "The importance of hydration"
- My Food Data: "Iceberg Lettuce"
- National Institutes of Health: "Vitamin K"
- My Food Data: "Celery"
- University of Illinois at Chicago College of Dentistry: "Eat Fruits and Veggies For A Healthy Smile"
- My Food Data: "Bok Choy"
- Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy: "Bok Choy"
- My Food Data: "Radishes"
- My Food Data: "Cucumber"
- National Institutes of Health: "Potassium"
- U.S. National Library of Medicine: "Phosphorus in diet"
- Mayo Clinic: "Dietary fiber: Essential for a healthy diet"
- My Food Data: "Watercress"
- Springerplus: "Phenolic profile and antioxidant potential of wild watercress (Nasturtium officinale L.)"
- My Food Data: "Tomatoes"
- National Institutes of Health: "Vitamin A"
- Memorial Sloan Kettering Cancer Center: "Lycopene"
- My Food Data: "Green Bell Peppers"
- National Institutes of Health: "Vitamin B6"
- My Food Data: "Watermelon"
- Cedars-Sinai: "What are Electrolytes?"
- My Food Data: "Zucchini"