Carbs in Watermelon: Will This Fruit Kick Your Out of Ketosis?

carbs in watermelon

Watermelons are 92% water with each juicy bite giving your high doses of Vitamin B6, A, C, and lots of antioxidants, lycopene, and amino acids.

It can be eaten as a snack or can be used as a versatile ingredient in any meal plan.

These fruits have become synonymous with picnics and summer thanks to their refreshing quality and sweet taste that combat heat and also rehydrate your body. 

How Many Carbs Are In Watermelon?

A cup (152 grams) of diced watermelon contains 141 grams of water and 11.5 grams of carbohydrates (Source).

That’s evidence that watermelons are indeed rich in carbs. Below are carbs concentrations in different serving sizes.

 (Sizing) Carb Amount (Grams)
100g 7.55
1 cup, balls (154g) 11.6
1 cup diced (152 g) 11.5
1 melon (15” long x7 ½ diameter (4518g) 341
1 wedge (approx. 1/16 of melon) 286g 21.6
10 watermelon balls (122g) 9.21
1 NLEA serving (280g) 21.1
Watermelon macros

From the table above, it’s easy to conclude that watermelons are high carbohydrate fruits especially if you’re on keto diet. For any food to be considered keto-friendly, it should have 5-10 grams per serving.

A good example is strawberries and cucumbers which have low carbohydrates per serving and are keto-friendly.

How Many Calories Are In Watermelon?

How Many Calories Are In Watermelon?
How many calories are in watermelon?

Like many fruits, watermelon is a low-calorie fruit. A cup of watermelon balls (154g) contains 46.2 calories. Below is a table that shows the number of calories in different watermelon servings.

Portion Amount (Calories)
100 g 30
1 cup, balls (154g) 46.2
1 cup diced (152 g) 45.6
1 melon (15” long x7 ½ diameter (4518g) 1360
1 wedge (approx. 1/16 of melon) 286g 85.8
10 watermelon balls (122g) 36.6
1 NLEA serving (280g) 84

On a ketogenic diet, 5-10% of your daily calories should come from carbohydrates. And because 1gram of carbohydrate equates to 4 calories, the recommended daily calorie intake ranges from 100-200 calories from 20-50grams of carbohydrates.

Watermelon can put you at the risk of getting kicked out of ketosis.

That’s because; a single serving will contribute 85 of your daily calorie requirement putting you close to your daily carbohydrate limit. That’s why it’s never recommended to eat watermelon on a keto diet.

Can You Eat Watermelon On The Keto Diet?

Watermelon joins the list of the many fruits and veggies that you shouldn’t eat on a keto diet because it’s high in carbohydrates and calories.

However, even though it’s not recommended to eat watermelon on the keto diet, you can always include this refreshing fruit in your daily meals but in minimal doses.

For example, you can opt only eat a cup of watermelon a day and keep tabs on your overall daily carb intake.

Eating Watermelon on a Keto Diet      

Eating Watermelon on a Keto Diet      
Is watermelon good for a keto diet?

While it’s best to avoid watermelon fruit if you’re on keto, there are different ways to incorporate it in your weekly diet without getting kicked out of ketosis:

  • Add small portions of this fruit into your keto-friendly salad recipes.
  • Only eat smaller portions –ideally not more than 1 cup a day- and ensure that you stay within your macros.

What Are The Health Benefits Of Eating Watermelon?

Studies have proved that there’s “more to watermelon than meets the tongue”- watermelon isn’t just water and sugar.

It’s a nutrient-dense fruit that provides high levels of minerals, vitamins, and antioxidants.

To get a better understanding of the health benefits of watermelons, let’s first look at the nutrition facts.

Watermelon Nutrition Facts

Below is the nutritional information for watermelon NLEA serving (280 grams)

  • Carbohydrates 21.1g
  • Calories 84
  • Protein 1.7g
  • Total Fat 0.4g
  • Potassium 314mg
  • Vitamin C 22.7mg
  • Vitamin A 1593 IU
  • Fiber 1.1g

1. Regulate Blood Pressure

According to a study on the American Journal of Hypertension website, watermelon extract plays a vital role in blood pressure regulation in obese people with hypertension.

Additionally, the amount of magnesium and potassium present in watermelons also plays a crucial role in lowering blood pressure.

Potassium is considered as a vasodilator- it helps in reducing tension in arteries and blood vessels, thereby enhancing blood flow and reducing stress on the cardiovascular.

The carotenoids in watermelons help prevent the hardening of artery and veins walls, hence contributing to blood pressure regulation, reducing chances of strokes, blood clots, atherosclerosis, and heart attacks.

2. Enhance Heart Health

Heart health on a keto diet
Heart health on a keto diet

A 2014 study suggests that carotenoid in watermelons may help improving heart functions.

Beta-carotene, best known for its anti-aging and antioxidant benefits, can help prevent age-related heart problems. Additionally, the roughage in watermelon, together with vitamin C, potassium, carotenoids help reduce cholesterol in the body hence keeping your heart safe from conditions caused by high cholesterol levels.

Watermelon fruit may be more important for older women.

A study conducted on postmenopausal women with increased aortic stiffness found out that women who took watermelons for two months saw decreased arterial stiffness and blood pressure compared to those who didn’t take watermelon extract.

These benefits can be attributed to arginine and citrulline found in watermelons.

3. Cancer Prevention

Like any other fruit, watermelons may play a role in preventing cancer thanks to their anti-oxidant properties.

According to the National Cancer Institute, lycopene found in watermelon has been linked to reducing prostate cancer cell growth.

4. Prevent Dehydration

According to research published in EXCLI Experimental and Clinical Sciences, watermelons are 92% water and play an important role in reducing both blood pressure and body temperature.

Watermelon fruit can also help you hydrate especially during those hot summer days. People in the tropics eat watermelon during the hot days to protect themselves from heatstroke.

Additionally, the high water content in watermelons helps the release of excess liquid in the body in form of sweat, which cools the body during sunny summer days.

5. Skin and Hair Benefits

Vitamin A is important for our skin, and a cup of watermelon contains a quarter of the daily recommended doses.

Vitamin A keeps the skin and hair moisturized and also promotes the growth of new elastin and collagen cells. Vitamin C in watermelon also helps in the growth of healthy collagen.


While watermelon is 92% water, almost all of its dry weight is carbohydrates. 

All the carbs in watermelons are simple sugars which when digested are known to cause spike in blood sugar levels. And for this reason, melons are not recommended for anyone on keto diet or other weight loss programs.

However you can enjoy watermelons only in tiny portions.