watermelon cut into slices

The health benefits of watermelon

A nutritionist explains watermelon's sugar content and why it's rich in vitamin A and beta-carotene. Discover our best recipes and how to get your 5-a-day.

What is watermelon?

Watermelon is a very large vine fruit that grows on the ground. It has a hard, green-striped skin which is inedible. Inside is a soft, bright pink-red flesh with black seeds, both of which can be consumed.


Watermelons are grown in many countries, including China, Turkey, Iran, Brazil and the United States. They need a long, warm growing season, around 80 days from seed, and are ready to be picked when the plants’ curly green tendrils start to turn yellow or brown, simply by cutting the melon from its stalk.

Depending on what country watermelons are grown in will determine their season. So, for example, in China their season starts from April, in the United States it runs from May to September, and Turkey is a bit later from July to November – hence why you can buy imported watermelon all year round in the UK.

Nutritional profile

Watermelon is largely made up of water (92%) and is low in calories with 31 calories per 100g. Being a fruit, it is primarily a carbohydrate with around 7g per 100g, and contains very little or negligible protein, fat or fibre.

Watermelon does contains a selection of vitamins and minerals but in very small amounts because of its high water content. However, its pink-red flesh means it is a good source of beta-carotene which converts to vitamin A when consumed. Vitamin A helps to keep our immune system, eyes and skin healthy.

There has also been some recent research into the phytonutrients found in watermelon, specifically L-citrulline – there is some research to suggest that this may help reduce the risk of colon cancer and lower blood pressure.

Is watermelon high in sugar?

Watermelon does contain sugar, 7g per 100g, but is not classed as a ‘high sugar’ food. Technically a food needs to contain 5g or less to be classed as low in sugar, and over 22.5g for a high sugar product. As watermelon is just above the 5g mark and it’s all natural sugars, it’s not regarded as a high sugar food.

How much watermelon counts as 1 of your 5-a-day?

An 80g serving of watermelon counts as 1 of your 5-a-day. This is roughly a 5cm thick wedge.

Can you be allergic to watermelon?

Yes, some people can be allergic to watermelon although this is rare. It may occur in those who are also allergic to other pollens, such as the ragweed pollen group, which includes bananas and cucumber, or grass pollens including dates, kiwis and peanut.

The signs of an allergy normally develop within seconds of consuming the food and includes tingling of the mouth and/or tongue, swelling of the face, eyes or throat and wheezing.

While some allergic reactions can be mild, they can also be life-threatening so if any signs of a severe allergy appear, such as breathing difficulties, trouble swallowing or speaking, or feeling dizzy and faint, call 999 immediately.

Read more from the NHS about food allergies and when to seek help.

How to buy the best watermelon?

Hit it! If you tap the underbelly and it’s ripe, it should sound hollow. Pick it up – if it’s ripe, it should feel heavy for its size. Also check the skin for any yellow spots which is a sign of aging.

Watermelon recipes

Watermelon & feta salad
Watermelon, prawn & avocado salad
Watermelon lollies
Watermelon salsa
Heirloom tomato & watermelon salad
Grilled aubergine, watermelon & sesame salad
Duck, watermelon & herb salad

Read more

The health benefits of bananas
The health benefits of kiwi fruit
The health benefits of cherries
The health benefits of grapefruit

This page was published on 16 July 2019.

Nicola Shubrook is a nutritional therapist and works with both private clients and the corporate sector. She is an accredited member of the British Association for Applied Nutrition and Nutritional Therapy (BANT) and the Complementary & Natural Healthcare Council (CNHC). Find out more at urbanwellness.co.uk.


All health content on bbcgoodfood.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other healthcare professional. If you have any concerns about your general health, you should contact your local healthcare provider. See our website terms and conditions for more information.