Is Watermelon Good for Kidney Patients? The Pros and Cons

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When you think of summertime, what images come to mind? Sitting by the pool, enjoying a cookout with family and friends, cooling off in the shade? Chances are, a slice of watermelon is included somewhere in that image. But what about watermelon for kidney patients? Can watermelon be safely included in your kidney-friendly diet? 

Chances are, yes. Watermelon is a nutrition powerhouse, filled with vitamins, minerals, antioxidants, and other nutrients that aid in your health. 

However, there are some instances where kidney patients may need to be cautious with the amount of watermelon included in their kidney-friendly diet. 

Let’s dive into everything you need to know about watermelon for kidney patients.  

The uses, benefits and cons of watermelon for kidney patients.

Watermelon 101

Watermelons, also called Citrullus lanatus, are a fruit that is native to the Kalahari desert in Africa.

Watermelon is thought to have been first harvested about 5000 years ago. Now, it is produced in tropical places across the globe. 

China is the top producer of watermelon in the world, followed by Turkey and India. 

Belonging to the Cucurbitaceae family, watermelon consists of flesh, rine, and seeds. The flesh is what is most commonly eaten. 

Water and carbohydrates are what mainly makes up watermelon.

However, watermelon also boasts plenty of vitamins, minerals, phytochemicals (plant chemicals), and antioxidants. Watermelon is mainly known for its high amounts of citrulline and lycopene.

Watermelon Nutrition

So, what is actually in watermelon? 

1 cup of raw, diced watermelon has: 

  • Kcals: 46
  • Water: 139 g
  • Protein: 1 g
  • Fiber: 1 g
  • Phosphorus: 17 mg
  • Potassium: 170 mg
  • Vitamin C: 12 mg
  • Iron: <1 mg 

1 slice of watermelon also has 1mg of oxalate. This is considered low oxalate.

Watermelon nutrition

What About Watermelon Juice?

Ideally, we like to include the whole fruit. The whole fruit often has more of the vitamins and minerals intact (including fiber!).  

However, let’s break down the nutritional content of watermelon juice: 

100g of 100% Watermelon Juice has: 

  • Kcals: 30 
  • Water: 91 g
  • Protein: 1 g
  • Fiber: <1 g
  • Phosphorus: 11 mg
  • Potassium: 112 mg
  • Vitamin C: 8 mg
  • Iron: <1 mg 

While watermelon juice does contain some nutrition, we really want to include the whole fruit as much as we can.

This way we can truly reap all of the many benefits that watermelon has to offer. 

Watermelon for Kidney Patients: Benefits

Let’s dive into some of the benefits of watermelon for kidney patients. 


Citrulline, also known as L-Citrulline, has long been associated with antioxidant and vasodilation properties.

This means that it can help keep our cells and heart healthy. 

The citrulline content is watermelon’s claim to fame. Watermelon is one of the best dietary sources of citrulline available. 

Benefits for Blood Pressure

Citrulline can help make arginine. Arginine and citrulline are amino acids, which are building blocks of protein.

Our body can create a substance called Nitric Oxide (NO) from these two amino acids.

Nitric Oxide can help open and relax our blood vessels. This is called vasodilation. This process can help lower blood pressure

Not having enough nitric oxide available in the body may contribute to poor blood flow and increased risk of high blood pressure as well as other heart problems. 

Since watermelon contains a high amount of citrulline, including it in your diet can be a good way to increase your body’s nitric oxide. 

Why is this important for your kidneys? The heart and kidneys are two organs that work together in our bodies.

Having high blood pressure can damage your kidneys. On the other hand, if your kidneys aren’t working well, it can make it harder to manage blood pressure. 

Including more foods that help control blood pressure can be a great way to care for your kidneys! 

We still need more research to truly understand the connection between watermelon and blood pressure.

However, if you are struggling with blood pressure control, talk to your dietitian about how watermelon can fit into your diet. 

Why watermelon should be included in your kidney friendly diet!


Do you ever wonder where the distinct, beautiful reddish pink color in the watermelon flesh comes from? Lycopene is the answer! 

For a while, tomatoes were what we normally associated lycopene. Yes, it’s true, tomatoes are a good source of lycopene. However, watermelon is too! 

Lycopene is a type of carotenoid. It is an antioxidant, which means that it can help prevent damage to our cells.

1 cup of raw watermelon contains approximately 4530 µg of lycopene. 

The antioxidant activity of the lycopene found in watermelon has many promising health benefits. 

Diets that are high in lycopene may be protective against certain types of cancers, particularly prostate and colorectal cancers. 

Lycopene may also be helpful for better heart health.

This powerful antioxidant can help decrease inflammation and protect cell damage. Inflammation and cell damage are both risk factors for cardiovascular disease. 

There are also studies that suggest that lycopene in the diet can help improve sleep hygiene, may be protective against certain neurological diseases, and can decrease general inflammation in the body.

However, we need more research to prove these claims. 

Watermelon for Kidney Patients: What to Watch Out For

Watermelon has many benefits for kidney patients. However, there are a few things to watch out for.


Some people with kidney disease need to follow a fluid restriction. The water that you drink needs to be factored into your daily fluid intake, but so does the water from your foods. Watermelon does contain fluids. This needs to be factored into your daily fluid allowance. 

1 cup of raw, diced watermelon has 139g of water. Talk with your dietitian about how watermelon can fit into your daily fluid needs. 


Watermelon contains potassium. Some people with kidney disease may need to limit the amount of potassium that they get from their diet. 

Remember, not everyone with kidney disease needs to follow a low potassium diet.

Be sure to talk to your doctor and dietitian about how much potassium is safe for you. 

If you do need to follow a low potassium diet, be mindful of the portion size of a watermelon that you include. 

1 cup of raw, diced watermelon contains 170mg of potassium.

This is considered a lower potassium serving. However, it is really easy to eat way more than just 1 cup of watermelon. 

2.5 cups of watermelon contains 425mg of potassium. This is considered a higher potassium item. 

Talk with your dietitian about how much watermelon you can include in your kidney-friendly diet!

To learn more about the low potassium diet, click here!

Is Watermelon OK For Kidney Patients With Diabetes?

Again, it comes down to portion size! 1 cup of raw, diced watermelon contains 12g of carbohydrates and approximately 1g of fiber.

There is also 9g of total sugars. 

The fiber found in fruit is what helps keep blood sugars under control. Watermelon only contains 1g of fiber in 1 cup. 

You may need to talk with your dietitian about what portion size of watermelon is best for you.

Also, be sure to ask if there are any foods you can combine with watermelon for better blood sugar control. 

So, watermelon can definitely fit into a renal diabetic diet.

However, you may just need to work with your dietitian to determine how to include it to be mindful of your blood sugars. 

Learn more about the renal diabetic diet here!

Ways to Use Watermelon 


Watermelon is delicious on its own. You can slice a watermelon into cubes, triangle-like slices, or scoop out parts of the flesh with a watermelon scooper. 

This classic summer treat can be enjoyed any time of the day, but can be so refreshing as a light afternoon treat!

Watermelon Fruit Salad

Try watermelon in a fruit salad! Slice your watermelon into 1-inch cubes or scoop out into 1-inch balls and pick 2-3 other fruits to combine with. 

For example, combine pineapple chunks, watermelon cubes, blueberries, and kiwi with a squeeze of lime juice to taste.

This is an easy and delicious summer salad! 

Easy Homemade Watermelon Sorbet

In the mood for a sweet treat? Try this watermelon sorbet recipe! Cut watermelon into chunks and freeze.

Once completely frozen, add to a blender or food processor with some lime juice to taste. Voila! An easy watermelon sorbet. 

To cut down on added sugar, skip the sweetener option! 

Swap regular ice cream for homemade watermelon sorbet!

Watermelon Popsicles

Have some popsicle molds handy? Try a homemade watermelon popsicle.

Just blend fresh watermelon and some lime juice and pour into your popsicle molds. Freeze overnight and enjoy the next day. 

You can get creative with your watermelon pops! Blend your watermelon with mint or rosemary to add some more flavor. 

Everything kidney patients need to know about watermelon!


So, what is the 411 on watermelon for kidney patients? The short answer is that watermelon can certainly fit into your kidney-friendly diet. 

In fact, watermelon can be helpful in reducing inflammation and keeping our cells safe and healthy.

Watermelon is also a good source of citrulline, which may help with better heart health and blood pressure. 

If you have a potassium restriction or need to follow a fluid restriction you may need to be mindful of the portion size of watermelon that you eat. 

Additionally, if you have diabetes and need to manage your blood sugars, talk with your dietitian about healthy ways to include watermelon in your diet. 

Overall, watermelon can be a refreshing treat this summer and has lots of kidney-friendly benefits. Enjoy!

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