Nutrition Ally Blog

Hydration Beyond Water: The Best Foods to Keep You Hydrated This Summer

Written by Cami Eastman, RDN, LD | 05/24/2026

Most people think hydration is simple: drink more water. But if you have ever gulped down eight glasses and still felt off, or wondered why some days you feel fine drinking far less, there is a good reason for that. Hydration is about more than how much you drink. It is also about what you eat.

Research consistently shows that between 20 and 33 percent of our daily water intake comes from food, not beverages. That means the choices on your plate have a real, measurable impact on how well your body holds onto fluids — especially during summer when heat and sweat increase your losses faster than most people realize.

Here is what the science actually says, and what you can do with it.

Why Food Matters for Hydration

Your body does not distinguish between the water in a glass and the water inside a slice of watermelon. Both count. What differs is how well your body absorbs and retains that fluid — and this is where food composition becomes interesting.

Fruits and vegetables are the obvious starting point. A 2013 study following over 400 children found that every additional 100 grams of solid fruits and vegetables consumed per day was associated with a meaningful improvement in hydration markers. That is roughly one medium piece of fruit or a generous side of salad. Not a dramatic change, but a consistent one.

Common high-water-content foods and their approximate moisture percentages include:

  • cucumber at around 96 percent,

  • lettuce at around 95 percent,

  • celery at around 95 percent,

  • tomatoes at around 94 percent,

  • strawberries at around 91 percent,

  • and watermelon at around 92 percent.

Adding these to meals across the day can contribute an extra 500 to 1,000 milliliters of water depending on how much you eat.

But water content alone does not tell the whole story.

Electrolytes: The Part Most People Miss

Plain water hydrates, but it does not always retain well. Your body needs electrolytes — particularly sodium and potassium — to hold onto fluid and distribute it where it needs to go.

A well-known study published in 2016 created what researchers called a Beverage Hydration Index. They measured how much urine different drinks produced over four hours compared to plain water. The drinks that caused the least urine output, meaning the best fluid retention, were oral rehydration solutions and milk — both of which contain sodium, carbohydrates, and protein. Sports drinks, coffee, tea, and orange juice performed no differently than plain water.

This does not mean you need sports drinks. It means the combination of electrolytes and a little energy in your food or drink is what makes fluid stick around longer in your body.

Practical examples of electrolyte-supporting foods include soups and broths, which provide both fluid and sodium; dairy products like milk and yogurt, which contain sodium, potassium, and protein; coconut water, which is notably high in potassium and comparable to commercial sports drinks for rehydration after exercise; and bananas and potatoes, which are reliable sources of potassium.

If you spend time outdoors in summer heat, pairing your fluids with salty foods — a broth-based soup, some crackers, a small handful of salted nuts — is a simple and effective strategy. It is not about adding salt for the sake of it. It is about giving your body the tools to actually use the fluid you are taking in.

Hydration and Digestion

This connection tends to surprise people: your gut needs water to work well, and what you eat affects both.

Adequate fluid intake is a first-line recommendation for managing chronic constipation, according to the American Society of Colon and Rectal Surgeons. But here is the nuance — drinking more water on its own does not reliably improve constipation if you are already reasonably hydrated. The evidence points to a combination approach: total dietary moisture from food and beverages together, alongside adequate fiber intake.

A large 2025 analysis using NHANES data — over 14,000 US adults — found a significant inverse relationship between total dietary moisture intake and constipation risk. People in the highest quartile of moisture intake had a 46 percent lower risk of constipation compared to those in the lowest quartile. That moisture came from both food and beverages combined.

The practical takeaway: if constipation is a concern, increasing water-rich foods alongside fiber-rich foods is more effective than simply drinking more glasses of water. Think soups with legumes, oatmeal with berries, salads with grains.

How to Build a More Hydrating Summer Plate

You do not need to overhaul everything. Small, consistent additions are what actually stick.

Start with breakfast. Including fruit — fresh berries, sliced melon, citrus — adds water and fiber simultaneously. A smoothie with yogurt and fruit contributes fluid, electrolytes, and protein in one go.

At lunch, lean into raw or lightly cooked vegetables. A salad with cucumber, tomato, and bell pepper adds water content and micronutrients. A broth-based soup, even a light one, adds sodium and fluid together.

For snacks, fruit and vegetables are your most straightforward options. Watermelon, grapes, celery with hummus, or a glass of milk all contribute meaningfully to total fluid intake.

During and after exercise in the heat, consider what you pair with your fluids. Plain water is fine for shorter, lighter activity. For anything over an hour in summer heat, electrolyte-containing options — coconut water, milk, a small salty snack alongside your water — help your body actually absorb and hold what you are drinking. Current sports medicine guidelines recommend drinking to thirst during exercise rather than following rigid volume targets, because overdrinking plain water during prolonged exertion can actually dilute your sodium levels and cause problems.

A Note for Specific Situations

For older adults, children, or anyone with a reduced sense of thirst, food-based hydration is especially practical. Eating hydrating foods does not require remembering to drink. It just requires eating — something that happens at regular intervals anyway.

For people managing constipation, combining fluid intake with fiber consistently outperforms either strategy alone.

For anyone spending extended time outdoors this summer — at the beach, doing yard work, exercising — the combination of adequate total fluids, electrolyte-containing foods, and drinking to thirst is the evidence-based approach. There is no magic formula or product required.

The Bottom Line

Staying hydrated in summer does not mean white-knuckling your way through eight glasses of plain water every day. It means eating a diet that includes water-rich foods, making sure you are getting electrolytes alongside your fluids, and paying attention to how your body feels — especially in the heat.

Food and fluid work together. Neither one is optional, and neither one has to be complicated.

If you want support building eating patterns that work for your body and lifestyle, that is exactly what nutrition counseling is here for. Ready to get started? Book a consultation directly by clicking here.

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