What is water?

Water is a colourless liquid composed of hydrogen and oxygen (H20). It is vital for life, although it supplies no calories. Drinking adequate amounts of water, or staying hydrated, is the first rule of health and nutrition. Our bodies can supposedly last weeks without food, yet just a few days without water. This makes sense when you realise our bodies are made up of about 60% water and that being dehydrated can affect us both physically and mentally.


Discover our full range of health benefit guides and some delicious ways to increase your water intake. Plus, find out how food affects your mood, 5 top tips to boost your energy and the top 5 benefits of exercise.

Pouring water into glass on a blue background

Nutritional benefits of water

The exact nutritional composition of your glass of water will depend on its source. Mineral and spring water, which are typically derived from underground reservoirs and springs, may provide additional nutrients in the form of minerals like calcium and magnesium.

What are the 5 top health benefits of drinking water?

1. May improve memory and mood

Research has shown that even mild dehydration may impair memory and mood in everyone from children to the elderly. Hydration impacts the brain, as well as the body, and research has shown that even mild dehydration may have a negative impact on moods and may heighten anxiety.

A lack of water may also increase the risk of a headache or migraines in some individuals.

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2. May aid weight maintenance

The brain can’t actually tell the difference between hunger and thirst, so often we mistake thirst as a ‘sugar craving’. The next time you feel the need for something sweet, try a glass of water first.

Staying hydrated may also help with weight maintenance. Research has shown that having water before a meal may fill you up more and therefore promote weight loss through suppressing your appetite. This was also noted in a 2015 study in which diet drinks were swapped for water. The results showed this may lead to greater reduction in weight and improved insulin resistance.

3. May improve exercise performance

There has been a lot of research into the effects of hydration or dehydration in athletes, and the results all pretty much conclude that dehydration not only affects sports performance but also physiological function too.

4. May prevent constipation

Water helps to ‘keep things moving’ in the digestive system, so staying hydrated may help prevent constipation in children, adults and the elderly. There is some evidence that fizzy water may be of particular benefit too.

5. May support the health of the urinary system

Poor hydration may increase the risk of developing, or the recurrence of kidney stones, in some individuals. Studies have also shown that drinking adequate amounts of water may reduce the risk of bladder infections and urinary tract infections, including cystitis, in women.

Is tap water safe for everyone to drink?

Tap water in the UK which complies with legal quality standards is safe for everyone to drink. However, if you are preparing a feed for a baby you should be sure to use unsoftened mains water.

The NHS recommends that the average adult consume 6-8 glasses or cups of hydrating fluid each day. This includes lower fat milks, and low sugar or sugar-free drinks, tea and coffee. However, this may vary dependent on your age, gender and activity levels. For example, you may need more water if you are exercising or when the weather is hot.

If you have concerns, speak to your GP or other healthcare provider.

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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 Nutrition and Lifestyle Medicine (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.

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