How Many Litres of Water to Drink a Day?

How many litres of water should I drink per day?

Question: How much water do we really need to drink per day?

If your immediate answer was “eight glasses,” hold tight a sec: it isn’t always that clear-cut. The current Australian dietary guidelines recommend consuming “plenty” of H2O, although they don’t state a specific amount. That’s because it’s determined by a series of individual factors, including what you eat, where you live and how much exercise you do. That said, experts generally recommend 2.1 litres (2100ml) for women and 2.6 litres (2600ml) for men.

What is the recommended daily water intake?

As per the Nutrient Reference Values for Australia and New Zealand, women should aim to drink 2.1 litres daily or approximately 8 glasses. For men, this jumps up to 2.6 litres or roughly 10 cups. These figures are based on the average weight of men and women, so if you’re underweight or overweight you should consider adjusting your fluid intake.

Additionally, those who engage in lots of physical activity, play sport, are on specific diets, pregnant, breastfeeding or ill should increase their water consumption. Accredited practicing dietician Natalie Von Bertouch tells New Idea Food that 25 millilitres per kilogram of bodyweight is a good rule of thumb.

Does the intake differ for men and women?

Because of the different makeup of our bodies, water consumption isn’t a one-size-fits all thing. Generally, men have faster metabolisms and higher levels of body fat. They also lose more water throughout the day via perspiration and need to drink more to replenish this as a result.

What about kids?

Similarly to adults, the water requirements for children are dependent on many factors including age and gender. The Better Health website lists the following guidelines:

Infants

0-6 months: 0.7 L/day (from breastmilk or formula)

7-12 months: 0.9L/day (from breastmilk, formula and other foods and drinks)

1-3 yr: 1.0 L/day (about 4 cups)
4-8 yr: 1.2 L/day (about 5 cups)

Boys
9-13 yr: 1.6 L/day (about 6 cups)
14-18 yr: 1.9 L/day (about 7-8 cups)

Girls
9-13 yr: 1.4 L/day (about 5-6 cups)
14-18 yr: 1.6 L/day (about 6 cups)

What are the benefits?

Aside from the fact that we need it to survive, there are so many reasons to increase your intake of H2O. These include:

Athletic performance

As water helps fuel our muscles by providing electrolytes, having a drink before or during a workout will boost energy levels and reduce the chance of cramps.

Weight loss

Research has found that that drinking half a litre of water within 30-40 minutes can increase your metabolic rate by up to 30 per cent.

Heart health

In one study, people who drank more than five glasses of water daily were 41 per cent less likely to die from a heart attack over a six-year period than those who drank two glasses or less.

Immunity

As well as carrying oxygen to our cells, water also plays a role in the production of lymphatic fluid. This is responsible for circulating white blood cells and nutrients to the body’s tissues and helping to fight off disease.

Skin

Water improves the appearance of skin by preventing dehydration and flushing out toxins and bacteria. Dry skin has less resilience and is more prone to wrinkles.

Digestion

Water assists in the removal of toxins and waste from the body and encourages regular bowel movements by helping dissolve fats and soluble fibre.

Brain power

Drinking eight to 10 cups of water per day has been shown to improve cognitive performance by up to 30 per cent.

Image: Getty

What happens if you don’t drink enough water?

As the human body is made up of 50 to 75 per cent water, dehydration can lead to severe complications including kidney stones, urinary tract infections and even death. It only takes a few days without water for the body to start to shut down. However, there are plenty of ways to tell if you might be dehydrated before it gets to this point.

Firstly, your urine should be a pale yellow, straw-like colour. If it appears dark yellow or orange you should sip some water immediately.

Other symptoms of dehydration include:

Brain fog
Fatique
Headaches
Dry skin, eyes and mouth
Constipation
Muscle cramps

What counts as water?

Von Bertouch recommends that 20-30 per cent our daily water intake should come from food, while the remaining 70-80 per cent should come from drinks – but not necessarily just the clear kind.

“Fluids like coffee, tea and milk count. Soda water too,” she explains. “You can even flavour your water with fresh fruit like lemon and oranges if you want to mix it up.”

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Lottie Dalziel

Lottie Dalziel, is a 4AM riser and coffee-addict who lives and breathes all things food. When she isn't reading up on the latest trends in sustainability or discovering ways to upcycle almost anything, you can find her by the beach, cooking up a storm or adding to her abundant (some would say out of control) plant collection.