Watermelon juice benefits: fresh red watermelon juice in an InstaCuppa portable blender and a glass with mint, beside watermelon slices on an Indian kitchen counter

Watermelon Juice Benefits: Empty Stomach, Weight Loss and Gastric Facts

May 2, 2026

By Saran Reddy, Founder - InstaCuppa | Published 2 May 2026 | 9 min read | Last updated: 28 October 2026

Watermelon juice benefits are simple. You get lots of water, few calories, and some lycopene and vitamin C.

The catch is the amount. India's diet guide wants you to eat the fruit more often than you drink the juice.

This guide covers the empty-stomach question, weight loss and gastric trouble. Every number links to its source.

In This Article

Watermelon juice by the numbers
7 benefits, with the studies
Empty stomach: is it safe?
Is it good for weight loss?
Is it good for gastric problems?
How to make it at home
Best combinations
Side effects and who should be careful
FAQs

What Is in a Glass of Watermelon Juice?

Quick answer: Watermelon is mostly water, about 91 to 95 g in every 100 g. It has 17 to 30 kcal per 100 g, some potassium and vitamin C, and a lot of lycopene. The juice keeps most of this, but loses some fibre.

Per 100 g of fruit	Indian watermelon (ICMR-NIN)	Global average (Health Canada CNF)
Water	94.5 to 95.3 g	91.5 g
Energy	70 to 85 kJ (about 17 to 20 kcal)	30 kcal
Vitamin C	11.5 to 13.3 mg	8.1 mg
Potassium	-	112 mg
Total sugars	-	6.2 g
Lycopene	-	4,532 micrograms

By the numbers: 100 g of Indian watermelon holds 94.5 to 95.3 g of water and 70 to 85 kJ of energy (ICMR-NIN, IFCT 2017).

The Indian figures come from the Indian Food Composition Tables 2017, codes E065 and E066. The global figures come from Health Canada's Canadian Nutrient File, food 1691.

The Indian fruit is a bit lighter and has more water. So we use the global numbers below, as the safe, higher guess.

Tender coconut water is even lighter, at 64 kJ per 100 g (IFCT code K002). So watermelon juice is light, but it is not the lightest drink in your kitchen.

7 Science-Backed Watermelon Juice Benefits

Quick answer: It hydrates and it is low in calories. It brings lycopene and vitamin C. It may ease sore muscles, help blood pressure and keep you full. Some studies used the whole fruit or an extract, not juice, and we say so below.

1. Hydration

Watermelon is 91 to 95% water by weight, per the tables above. On a hot day, a glass adds to your fluid for the day.

It is not magic, though. Plain water still does most of the work.

2. A low-calorie swap for cold drinks

A 250 ml glass of plain juice has about 75 kcal, at 30 kcal per 100 g. That is far less sugar than most packed fruit drinks.

Make it with no added sugar. See how in our no-sugar watermelon juice recipe.

3. Lycopene for your skin

100 g of watermelon has 4,532 micrograms of lycopene. A raw tomato has 2,573 (Health Canada CNF, food 2460).

In one trial, people took about 10 mg of lycopene a day for 12 weeks. Sunburn redness fell by up to 48% in the tomato-drink group (Aust et al., 2005).

A big glass of watermelon juice carries a similar daily dose. But the trial used tomato products, so this is a hint, not proof.

Keep using sunscreen.

4. Less muscle soreness

In a small trial, seven athletes drank 500 mL of watermelon juice with 1.17 g of L-citrulline before hard cycling.

The paper says "Both watermelon juices helped to reduce the recovery heart rate and muscle soreness after 24 h" (Tarazona-Díaz et al., 2013). Seven people is a very small study.

5. Blood pressure support

In a 6-week trial, 14 adults with raised blood pressure took a watermelon extract. Their top BP number fell by 15.1 mm Hg against a dummy pill (Figueroa et al., 2012).

That was a concentrated extract, not a glass of juice. Never swap your BP tablets for juice.

6. Vitamin C

Indian watermelon gives 11.5 to 13.3 mg of vitamin C per 100 g, per ICMR-NIN. Your body uses vitamin C to make collagen.

A glass helps a little. Amla, guava and oranges give far more.

7. Feeling full

In a 4-week trial, 33 overweight adults ate 2 cups of watermelon a day. At other times they ate cookies with the same calories.

The fruit left them less hungry.

The study found that "Watermelon consumption significantly decreased body weight, body mass index (BMI), systolic blood pressure and waist-to-hip ratio" (Lum et al., 2019). This was whole fruit, which keeps its fibre and bulk.

Watermelon Juice on an Empty Stomach: Is It Safe, and When Should You Drink It?

Quick answer: Yes, watermelon juice on an empty stomach is safe for most healthy adults. Keep the first glass small, about 150 ml. Some people get gas or loose motions, because watermelon is high in fructose. If that is you, drink it after a light snack.

No study shows that fruit on an empty stomach is harmful. The real issue is fructose.

Monash University leads gut-diet research for IBS. It writes: "Fruits particularly high in excess fructose include apples, pears, mangoes, cherries, figs, nashi pears, pears, watermelon and dried fruit" (Monash FODMAP).

A big glass on an empty stomach sends a lot of fructose to your gut at once. People with fructose intolerance feel it most.

For them, says a Cleveland Clinic article, "an innocent wedge of watermelon or a handful of raisins can be a total day wrecker" (Cleveland Clinic).

ICMR-NIN also caps the amount. "Fresh fruit juices from not more than 100 to 150g whole fruits can be consumed occasionally by adults" (Dietary Guidelines for Indians 2024).

150 g of watermelon gives roughly 120 ml of juice. So a small glass is the sensible size.

Best time to drink watermelon juice: use this table.

Situation	Is it a good time?	Tip
Morning, empty stomach	Fine for most people	Keep it to a small glass, about 150 ml
Mid-morning or afternoon	Best everyday slot	Have it with or after a light snack
Before exercise	Good	The athlete trial gave the juice before the test
With a big meal	Okay	Count it as part of the meal's sugar
Last hour before bed	Skip	A big glass of fluid can wake you at night

If you like a morning drink, compare it with lemon honey water on an empty stomach.

Watermelon juice peene se kya hota hai? (pine ke fayde)

तरबूज का जूस पीने से शरीर को पानी, पोटैशियम और विटामिन सी मिलते हैं। इसमें कैलोरी कम होती है, इसलिए यह ठंडे पेय की जगह ले सकता है।

खाली पेट छोटा गिलास ठीक है।

In English: watermelon juice gives your body water, potassium and vitamin C. It is low in calories, so it can replace a cold drink.

A small glass on an empty stomach is fine.

தர்பூசணி ஜூஸ் நன்மைகள் (Tamil)

தர்பூசணி ஜூஸில் நீர், பொட்டாசியம் மற்றும் வைட்டமின் சி உள்ளன. இதில் கலோரி குறைவு.

சர்க்கரை சேர்க்காமல், சிறிய கிளாஸ் அளவில் குடிக்கவும்.

In English: watermelon juice has water, potassium and vitamin C, and few calories. Drink a small glass with no added sugar.

Is Watermelon Juice Good for Weight Loss?

Quick answer: Only as a swap. A glass of plain watermelon juice in place of a soft drink cuts calories. But ICMR-NIN asks people trying to lose weight to avoid fruit juices, and the weight-loss trial used whole watermelon. For weight loss, eat the fruit.

India's diet guide is direct. To keep a healthy weight and waist, one "must avoid sugar, processed products, fruit juices and HFSS foods" (ICMR-NIN).

It also says "Fresh fruits are nutritionally superior to freshly prepared fruit juices". The fruit keeps its fibre and fills you up more.

ICMR-NIN limit: Fresh juice from no more than 100 to 150 g of fruit, taken now and then (DGI 2024). That is about 120 ml of watermelon juice.

The World Health Organization agrees on the sugar. Its free sugars include "sugars naturally present in honey, syrups, fruit juices and fruit juice concentrates" (WHO, 2015).

So does watermelon juice increase weight? Not one glass does.

But three big glasses a day add up like any sweet drink.

The good news is the fruit. In the 4-week trial above, whole watermelon beat cookies on hunger and body weight.

Want a lighter drink for summer? See our cucumber juice benefits guide.

Is Watermelon Juice Good for Gastric and Acidity?

Quick answer: Often yes, if you mean acidity. Watermelon is low in acid, with a pH of 5.18 to 5.60, so it is gentler than lemon or orange juice. If your gastric trouble is gas and bloating, watermelon may make it worse, because of its fructose.

A Kansas State University food chart lists "Watermelon 5.18-5.60" for pH (K-State pH chart). Lemon and orange are far more acidic.

Gas is a different story. The excess fructose noted by Monash can ferment in the gut and cause bloating in people with IBS.

Try a small glass after food, and see how you feel. Our guide to juices that help with gastric and acidity lists gentler options.

How to Make Watermelon Juice at Home

Quick answer: Cut 2 cups of watermelon into cubes, remove the big seeds, and blend for about 30 seconds. Watermelon is soft, so most people skip straining. Drink it fresh, with no added sugar.

Mixer grinder way: blend the cubes with 2 or 3 ice cubes. Strain through a fine sieve if you want it smooth.

Portable blender way: drop the cubes into the bottle and blend. You drink from the same bottle, so there is less to wash.

Not sure if you need a juicer? Our portable blender vs juicer guide explains why blending keeps more fibre.

InstaCuppa Portable Blender (4000 mAh, 230 W, 500 ml)

Blend watermelon juice in the bottle you drink from.

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InstaCuppa Portable Blender Bottle (6000 mAh)

Bigger battery, with an LED display for battery status.

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Best Watermelon Juice Combinations

Quick answer: The best mixes are watermelon with mint, lemon, ginger or cucumber. Each changes the taste without adding sugar. Add the extra item to the blender with the cubes.

Combination	Add to 2 cups of cubes	Taste
Watermelon + mint	6 to 8 mint leaves	Cool and fresh
Watermelon + lemon	Juice of half a lemon	Tangy and bright
Watermelon + ginger	1 small piece of ginger	Warm, with a kick
Watermelon + cucumber	Half a cucumber, peeled	Mild and light

Mint is the most popular pick for hot afternoons. Lemon adds tang, so you will not miss sugar.

For more ideas, try our 34 summer drinks for a portable blender.

Watermelon Juice Side Effects and Who Should Be Careful

Quick answer: Watermelon juice is safe for most people in small glasses. Too much can cause gas or loose motions. Take extra care if you have diabetes, kidney disease, IBS or a pollen allergy.

Diabetes: old GI tables gave it a high GI of 76. The 2021 tables found a low GI of 50 (University of Sydney GI group).

Either way, the glycemic load for 120 g of fruit is low, about 4 to 6. Juice drops the fibre, so ask your doctor and prefer the fruit.

Kidney disease: the National Kidney Foundation puts it on its low-potassium list. The list says "Watermelon (limit to 1 cup)" (National Kidney Foundation).

It also warns, "Serving size matters. A large serving of low-potassium food can turn into a high-potassium food." (NKF).

Follow your renal diet chart.

IBS or fructose intolerance: Watermelon is high in excess fructose, per Monash. Start with a few sips, not a full glass.

Pollen allergy: ACAAI, a US allergy group, says people may react to foods "such as cantaloupe or watermelon with ragweed allergy" (ACAAI).

An itchy mouth or lips after watermelon is a sign to stop and see a doctor.

A quick note: This article shares general food and wellness information for Indian readers. It is not medical advice. Bodies differ. If you are pregnant, unwell, or managing a health condition, please ask your doctor before making changes.

Frequently Asked Questions

Can I drink watermelon juice on an empty stomach?

Yes, most healthy adults can. Keep it to a small glass of about 150 ml. If you get gas or bloating, have it after a light snack instead.

Is watermelon juice good for weight loss?

It can replace a sweet cold drink, which helps. But ICMR-NIN asks people trying to lose weight to avoid fruit juices. The weight-loss trial used whole watermelon, so eating the fruit is the better choice.

Does watermelon juice increase weight?

Not by itself. One glass has few calories. Large glasses every day still add sugar, and WHO counts the sugar in fruit juice as free sugar.

Is watermelon juice good for gastric problems?

It is a low-acid fruit, so it is gentler than citrus for many people. But it is high in fructose, which can cause gas in people with IBS or fructose intolerance.

Can I drink watermelon juice every day?

ICMR-NIN says fresh juice from 100 to 150 g of fruit can be had occasionally by adults. On most days, eat the fruit instead.

When is the best time to drink watermelon juice?

Have it mid-morning, in the afternoon or before a workout. Skip a big glass in the last hour before bed.

Is watermelon juice safe for diabetics?

Its glycemic load per small serving is low. Still, juice has no fibre to slow the sugar, so diabetics should ask their doctor and prefer the fruit.

Watermelon juice peene se kya hota hai?

Tarbooj ka juice peene se body ko paani, potassium aur vitamin C milta hai. Calories kam hoti hain, isliye yeh cold drink ki jagah le sakta hai. Chhota glass hi piyein.

Sources & References