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Are watermelons low in sugar?
Yes, watermelons are low in sugar compared to many other fruits.
In fact, a full cup of diced watermelon contains only about 9 grams of natural sugar.
That’s significantly less than what you’d find in a cup of grapes, mangoes, or bananas.
But if you’ve been wondering, are watermelons low in sugar, the short answer is yes, though there are a few important details to keep in mind.
In this post, we’ll take a closer look at why watermelons are low in sugar, how their sugar content compares to other fruits, and what that means for your diet.
Let’s get to it.
Why Watermelons Are Low in Sugar
Watermelons are low in sugar, and here’s why:
1. Watermelons Are Mostly Water
The main reason watermelons are low in sugar is that they’re about 92% water.
That high water content means there’s simply less room for sugar in every bite.
When you eat a slice of watermelon, you’re mostly hydrating yourself, not loading up on sugar.
This is also why watermelon feels so refreshing on a hot day and why it’s a go-to fruit for anyone watching their sugar intake.
2. Low Sugar Per Serving Compared to Other Fruits
If you’re asking whether watermelons are low in sugar, comparing them to other fruits helps put things in perspective.
A cup of watermelon has roughly 9 grams of sugar.
Compare that to a cup of grapes at around 23 grams, a cup of mango at 23 grams, or even a medium banana at 14 grams.
Even apples and oranges, which are often praised as healthy choices, pack more sugar per cup than watermelon.
So yes, watermelons are genuinely low in sugar when you stack them up against the fruit aisle competition.
3. Low Calorie Density
Because watermelons are low in sugar and high in water, they’re also low in calories.
A whole cup of diced watermelon comes in at just around 46 calories.
That makes watermelon one of the most diet-friendly fruits you can snack on.
You get sweetness, volume, and hydration without a heavy sugar or calorie load.
4. Natural Sugars, Not Added Sugars
It’s important to remember that the sugar in watermelon is natural fructose, not added sugar.
Your body processes natural sugars from whole fruit differently than refined sugar.
The fiber and water in watermelon also help slow down how quickly that sugar hits your bloodstream.
So even though watermelons contain sugar, it’s not the kind you need to fear in a balanced diet.
Are Watermelons Low in Sugar for People with Diabetes?
This is where things get a little more nuanced.
Yes, watermelons are low in sugar per serving, but they do have a high glycemic index.
The glycemic index measures how quickly a food raises blood sugar.
Watermelon ranks high on that scale, around 72 to 80.
But here’s the catch — glycemic index only tells part of the story.
What really matters is glycemic load, which factors in portion size.
Since watermelons are low in sugar per serving and mostly water, their glycemic load is actually quite low.
That means a modest slice of watermelon won’t spike your blood sugar the way a high-glycemic, high-carb food would.
If you have diabetes, watermelons can still fit into your diet when eaten in reasonable portions.
Pairing watermelon with protein or healthy fat can slow sugar absorption even more.
How Much Sugar Is in Watermelon Really?
Let’s break down the actual numbers so you can see for yourself.
1. Sugar Content by Serving Size
One cup of diced watermelon contains about 9.4 grams of sugar.
A small wedge, roughly 1/16 of a whole melon, has around 5 to 6 grams.
A large slice, closer to 1/8 of the melon, can have around 11 to 12 grams.
So the question of whether watermelons are low in sugar really depends on how much you eat.
Stick to a cup or a small wedge, and you’re firmly in low-sugar territory.
2. Sugar Content in Watermelon Juice
Watermelon juice concentrates the sugar because you’re drinking multiple servings at once.
A 12-ounce glass of watermelon juice can easily contain 20 grams of sugar or more.
So while watermelons are low in sugar as a whole fruit, juicing them changes the equation.
Whole fruit is always the better choice when you’re watching your sugar intake.
3. Dried Watermelon Is a Different Story
Dried watermelon strips away the water, which concentrates the sugar dramatically.
A small handful of dried watermelon can have as much sugar as two or three cups of fresh watermelon.
So if you’re wondering whether watermelons are low in sugar, make sure you’re eating them fresh, not dried.
So, Are Watermelons Low in Sugar?
Watermelons are low in sugar, especially compared to most other fruits.
A cup of diced watermelon has only about 9 grams of natural sugar and roughly 46 calories.
That’s because watermelons are over 90% water, which naturally dilutes their sugar content.
For most people, including those managing diabetes, watermelon can be a healthy, hydrating treat in reasonable portions.
Just keep an eye on serving size, skip the juice and dried versions, and enjoy this refreshing fruit guilt-free.