Why Watermelon Is Good for Weight Loss (Not Fattening)

Is watermelon good for weight loss, or is it fattening? Good news! Eating watermelon doesn’t make you fat and can even possibly help you lose weight.

Watermelon is a delicious and sweet summer treat that’s packed with nutrients and high water content. It’s great being able to enjoy this delicious, hydrating fruit that also helps you shed some extra pounds.

While watermelon itself doesn’t cause weight gain, you should be aware of some concerns before adding a lot of it to your diet. Like most fruits, watermelon contains sugar that could possibly hinder some people’s weight loss plans.

Keep reading to discover how you can maybe lose weight and even lose belly fat just all while eating and enjoying watermelon.

Watermelon Can Help You Lose Belly Fat

Quick Answer: Watermelon does contain sugar and is high on the glycemic index, but it’s low in calories. The fiber and water content drastically lower the glycemic load. So, watermelon can help satisfy your sweet tooth while still helping with weight loss.

Watermelon is a healthy fruit that’s mostly water (92%) and contains the essential nutrients:

  • Vitamin C
  • Vitamin A
  • Potassium
  • Magnesium
  • Vitamins B1 and B6
  • Fiber
  • Lycopene

Watermelon is also low in calories, with 1 cup containing only 46 calories. This makes it one of the least calorie-dense foods. But there is also almost 10g of sugar in 1 cup of sliced watermelon.

Is watermelon high in sugar?

Watermelon has a glycemic index of 72 out of 100, which is high. The glycemic index (GI) measures how quickly a food can raise your blood sugar levels. Generally, the lower the better, since high GI foods can lead to weight gain and insulin resistance.

But watermelon’s glycemic load (GL) is relatively low, at only 4 per serving. The glycemic load combines how much food affects your blood sugar and the whole portion size. It gives a more accurate representation of a food’s impact on your blood sugar in the real world.

So, while watermelon’s GI may be high, and it does contain a good amount of carbs, its relatively low GL and high water and fiber content make it much less likely to spike your blood sugar when eaten in reasonable amounts.

Why Watermelon Boosts Weight Loss

Eating watermelon can help with losing weight and belly fat, but why?

First of all, overeating on anything can cause you to gain weight due to being in a calorie surplus. But having some diced watermelon wouldn’t be a main driving force because it’s relatively low in calories and has a low glycemic load.

Usually the main reason for weight gain comes from bad eating habits like consuming too many calorie-dense foods, processed foods, refined foods, seed oils, and sugary drinks. You’ll lose weight much easier following a healthy diet by simply swapping out these bad foods for fruits like watermelon.

If your body doesn’t handle sugar well due to diabetes or insulin resistance, you may want to limit your watermelon intake. Those with a natural endomorph body type (easier to store fat + slower metabolism) may also benefit by keeping their carbohydrate and sugar intake low when trying to lose weight.

It’s important to have metabolic flexibility, which is your body’s ability to switch between burning carbs and fat for energy easily. But if you have metabolic inflexibility, your body has a worse ability to switch between burning carbs and fats for energy.

The sugar in watermelon is also processed differently in your body than table sugar. Watermelons have sugar in the form of fructose, which is mostly processed in your liver. Then via a process called lipogenesis, the fructose can be converted into triglycerides (type of fat).

High fructose intake from consuming an extreme excess of fruit sugar can cause your body to produce too many triglycerides. But just a small amount of watermelon shouldn’t be much. A concern is consuming too much high fructose corn syrup or sugary drinks, which could then easily lead to weight gain.

If your body has a harder time processing sugar and has reduced metabolic flexibility then you may want to try taking a “carb controller.” A carb controller can help to blunt the blood sugar response from eating sugar and carbs while also improving your body’s ability to use those sugars for energy instead of storing them as fat.

My Pick
BioTrust IC-5

A Premier-Quality Formula for Supporting Healthy Blood Sugar Metabolism.

  • Features a premium blend of ingredients (Berberine, Cinnamon, Chromax┬«, Benfotiamine, and Naringin) to support healthy carbohydrate metabolism
  • Supports healthy blood sugar metabolism
  • Helps maintain healthy blood sugar levels
  • Assists with weight management

How Much Watermelon Should You Eat to Lose Weight?

If you really want to, you can eat watermelon every day as long as the rest of your diet is healthy and balanced. If you’re eating too many sugars and carbs in the rest of your diet, then adding watermelon on top of it every day probably isn’t the best idea.

Watermelon is mostly water, fiber, vitamins, minerals, and sugar. Having it every day isn’t a big deal and can have some health benefits from the nutrients. The sugar won’t be that big a deal, considering the glycemic load, as long as your portions are small to moderate size.

One cup of sliced watermelon is a healthy serving size equal to one or two slices. 2 cups of sliced watermelon would equal about 100 cal and 20g of sugar. This isn’t too much sugar, considering it helps you feel fuller while satisfying your sweet tooth.

Eating watermelon can be a helpful appetite suppressant while dieting to help you drop pounds. Hunger is one of the most challenging parts of dieting, so the easier it is to curb hunger, the better your chances of getting results.

Sometimes watermelon can make you feel bloated because of its high water, sorbitol (sugar alcohol) and fiber content. But this isn’t belly fat and just temporary bloating.

Watermelon is sweet and can help to satisfy your sweet tooth. If you’re craving sugar, it’ll be much healthier for your waistline to eat a slice of watermelon than eating a donut

What’s the best time to eat watermelon?

The best time to eat watermelon for weight loss would be earlier in the day rather than at night. Eating watermelon earlier in the day allows you time to burn off the sugars for fuel. Eating watermelon at night can contribute to weight gain because the sugars won’t be burned for fuel and could instead be deposited as body fat.

Drinking water right after eating watermelon is probably isn’t a good idea because it could upset your digestive tract. It’s believed that water consumed with fruits can upset the digestive process and cause an upset stomach. Watermelon already has a high water content, so you shouldn’t need more immediately.

The Watermelon Diet

The watermelon diet is a short dieting plan that involves eating a large amount of watermelon. The thought is watermelon good for weight loss since it’s low in calories and high in water content.

Following a strict watermelon diet is believed to help flush out toxins and and cleanse your body due to it having a high amount of water. If you are doing a watermelon diet then it would be a good idea to add other healthy foods such as lean proteins, veggies and healthy fats.

Well, it is possible to lose weight only by eating a watermelon diet. But following a strict watermelon diet is definitely not advisable. Your body needs other nutrients, such as protein and healthy fats, to go along with the sugar in watermelon to be healthy and contribute to weight loss.

Many try the watermelon diet because it helps them feel full, tastes sweet, and is low in calories. You could try the watermelon diet for 3 or even 5 days and expect some weight loss.

But the watermelon diet won’t be healthy in the long run because, without protein, your body will start losing muscle mass over fat, contributing to your becoming “skinny fat.” For rapid weight loss, it is best to consume a low-calorie and low-carb diet with high amounts of protein and fiber.

Keep in mind that if you do decide to do a watermelon diet, it should only be for the short term, and it’s not sustainable for long-term use. But the watermelon diet could be a way to kickstart your weight loss journey and get some quick results. Just remember to use caution when doing the watermelon diet and to talk to your physician first.


  • If your diet involves eating a lot of sugars and carbs then adding watermelon on top of that may not be the best idea. If your glycogen stores become full, your body will dump the rest of these sugars and carbs as fat. But watermelon is perfectly acceptable as part of a healthy diet and can help you lose weight.
  • Watermelon, and other sweet fruits, are best when eaten in season during the summer months when people are more active. Being more active allows your body to quickly burn up these sugars for energy, and further minimizes the chances of them being stored as fat.
  • Watermelon might contain some sugar, but satisfying your sweet tooth is healthier with watermelon than eating a cake. And if it helps you feel full, this can curb hunger, making it easier to stick to your overall diet.
  • Like with everything, moderation is key; stick to eating only a small portion of watermelon. Otherwise, the sugars can quickly add up to a lot. But watermelon is refreshing and delicious, so you shouldn’t worry about having a little bit here and there without it causing you to gain weight.