Water is an essential nutrient. It is necessary to sustain all forms of life, and humans can only live a few days without it. It is also a healthful drink.
It seems like every celebrity puts their good skin or toned physique down to ‘drinking plenty of water’. But water isn’t the latest food fad – it performs a range of vital functions in our body.
Why our bodies need water
Water makes up about 60% of our body weight, and it’s involved in every single process in our body.1 We need it to:
• help regulate our temperature
• keep our joints, eyes and muscles lubricated
• get rid of waste via sweat, urine or bowel movements
Water is essential for life. Without it, we would only be able to survive for a few days.2
What happens if you don’t drink enough water?
Dehydration can affect your body and brain in a number of ways. You may feel tired, find it hard to concentrate, experience mild memory problems, lack motivation – especially when it comes to exercise – or find it takes more effort during a run or gym session.3
You can tell if you’re drinking enough by checking the colour of your wee. It should be a pale-yellow colour.4 Dark, cloudy or strong-smelling urine is a sign you’re dehydrated, so start upping your fluid intake as soon as possible.
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How much water should you drink?
The rule that we should drink eight glasses of water a day is not technically true.
Research published in the British Medical Journal in 2007 explored where the idea that we need eight glasses every day for hydration comes from.5 Researchers found that this figure is based on 1945 study, which stated we need 2.5 litres of water a day – but that most of this could be found in our food.
It’s this last bit of information (that most water can be found in our food) that has been forgotten over the years and so the study has been misinterpreted as claiming we need eight glasses of water a day
The NHS says we should drink six to eight glasses of fluid a day, about 1.2 litres.6 This includes water, lower-fat milks, tea and coffee. And don’t worry that tea and coffee can cause dehydration.
Although they are diuretics, which make you wee more often, a 2003 study by the School of Sport and Exercise Sciences at Loughborough University found there was no evidence that coffee led to dehydration.7 The study concluded that coffee actually had ‘similar hydrating qualities’ to water.