Water - how much do we need?

 18 Dec 2015

Water plays a vital role in our health and is essential for many bodily functions to work properly. Some of the key roles water plays include transporting nutrients and blood throughout our body, removing toxins and waste from the body, replenishing blood supply and keeping our vital organs healthy.

Yet despite its importance, studies have found that as many as three quarters of Australians are ‘chronically dehydrated’. [i]

Dehydration can be serious

Dehydration occurs when you lose more fluid than you take in. It can lead to several side effects, ranging from mild to life threatening. Mild dehydration will leave you feeling thirsty, tired and light-headed and could lead to constipation [ii].

Left untreated, dehydration can become serious. Severe dehydration requires urgent medical attention. Typical symptoms may include may include irritability and confusion; dry skin and shrunken eyes, rapid heartbeat, fever, seizures or unconsciousness. Severe dehydration can also result in kidney failure, coma or death [iii]. 

While serious dehydration is rare, researchers at the University of Barcelona found that being dehydrated by just two per cent impairs performance in immediate memory skills, and psychomotor skills — the relationship between cognitive (thinking) functions and physical movements. [iv]

How much should we drink?

For years we were told to drink between six to eight glasses of water each day. Now, Kidney Health Australia recommend drink according to our thirst and make water our preferred beverage. We should also limit drinks high in sugar, caffeine and alcohol [v]

Remember however, that if you are pregnant or breastfeeding, live in hot or humid conditions, or exercise, you may need to increase your water intake.

If you have a pre-existing medical condition, speak to your doctor. Some conditions (e.g. pregnancy, breastfeeding or illnesses that cause vomiting or diarrhoea) require you to drink more water. Other conditions such as end-stage kidney failure and some cardiac and respiratory conditions, require a decreased water intake.

How to drink more water

It sounds easy enough, but many Australians struggle to drink adequate water. If you find it difficult to drink enough water each day, why not try sipping on a water-filled drink bottle throughout the day, or drink a glass of water with each meal. 

You can also increase your water intake by swapping sugary, caffeinated drinks with herbal teas or mineral water. If the taste of water just doesn’t get you excited, you can add a squeeze of fruit juice or slices of citrus fruit to liven things up.

While most of our fluid intake for the day is related to what we drink, about 20 per cent is found in our foods, some of which are high in water content (e.g. cucumber and watermelon). Tea, coffee and milk also contain water.

If you’re looking for a drink that’s not only hydrating but tasty, then try the recipe below.
Watermelon and cucumber frappe


4 cups of watermelon flesh, cut into chunks
½ cup frozen raspberries
½ cup, chopped cucumber (skin on is fine)
juice from 1 lime (about 2 tablespoons)
8-10 fresh mint leaves (plus extra for garnish)
¾ cup cold water
1 teaspoon honey (optional)

Place watermelon in freezer until frozen solid.

In a blender, combine frozen watermelon, raspberries, cucumber, juice, water, mint leaves, water and honey. Blend until combined. Pour into serving jug and garnish with extra mint leaves.


[i] Blue Planet, Water Facts; published not specified; accessed 19 September, 2015

[ii] Mayo Clinic, Dehydration: Symptoms; last updated 12 February 2014; accessed 19 September 2015, http://www.mayoclinic.org/diseases-conditions/dehydration/basics/symptoms/con-20030056

[iii] Ibid.

[iv] Adan A, Cognitive performance and dehydration, Journal of the American College of Nutrition, 2012 Apr;31(2):71-8; accessed 19 September 2015, http://www.ncbi.nlm.nih.gov/pubmed/22855911

[v] Kidney Health Australia, Thirsty — Drink water instead, last updated 7 July 2015; accessed 19 September 2015, http://www.kidney.org.au/kidneydisease/drinkwaterinstead/tabid/703/default.aspx