How much water do you need to drink and tips to keep hydrated 

Kara Vogt

How much water do you need to drink and tips to keep hydrated 

Written by
Kara Vogt

How much water do you need to drink and tips to keep hydrated 

The age old recommendation of needing 2 litres of water a day is a familiar one. But did you know that it might not be the right amount for you? 

While it’s true that water makes up roughly 70% of our total body weight, and is an essential part of almost all bodily functions, the amount you need varies greatly from person to person. The magic number is linked to your body weight, activity levels, and the climate you live in. 

Another important factor is the amount of lean body mass a person has. This is generally higher in males, and decreases with age. So males will need more water than females, and the requirement for older people is less. 

Water is lost by the body every day through sweat, urination, and via your stomach secretions to digest and absorb food. For healthy adults, the estimate daily losses are 2.5 – 3L per day, so all of this needs replacing. Importantly though, and sometimes misunderstood, is that not all of this has to come from water – food contains a lot of fluid too! For example, the milk on your breakfast cereal could provide 200ml of fluid, a bowl of pasta provides up to 300ml of fluid, and many vegetable are 90% or higher water content. 

You can use your appetite and thirst to guide you to drink enough, but some situations need a more deliberate effort, like in very hot weather, with exercise, if you’re unwell or for the elderly. 

Avoiding dehydration is incredibly important, as it has been shown to negatively affect both mental and physical function. Only a minor reduction in your body’s hydration level can lead to poorer coordination, reduction in brain cell function, and changes to mood and concentration. 

How to know if you’re having enough water

You can monitor your hydration easily by paying attention when you go to the bathroom! In the morning, it is normal for urine to be darker in colour as it has become concentrated overnight. A light yellow colour should be seen by the middle of the day, and towards the end of the day it should be almost clear. This is a good sign you’re getting enough water. 

Try these tips to increase your water intake 

- Keep a water bottle with you whenever you go. If it’s your work desk, next to you on the couch, or in the car, you can have regular sips throughout your day.

- When you exercise, your need for water increases. Aim to have one litre of water for each hour of exercise, in addition to your usual day’s intake.

- Have a glass of water before you sit down to eat a meal, and first thing when you get up in the morning.

- Add a squeeze of lemon or a few berries into your water to make it that little bit more appealing.


Can you drink too much water?

Having too much water can be very dangerous to your health, as your kidneys cannot cope to get rid of a lot of fluid quickly, and your blood becomes diluted. This is rare in the general population and would mean drinking several litres of water in a short amount of time. 

Foods to avoid to stay hydrated

Alcohol and caffeine can have a big impact on your hydration. The metabolic process of breaking down alcohol in your body requires a lot of water, so you can quickly become dehydrated. Caffeine can cause your body to excrete more water in your urine. 

Salty foods like chips, processed meats and salted nuts, can make you thirsty because the salt binds to water in the body. High sugar drinks like fruit juice can have a similar affect when consumed in large amounts. The sugar can bind to water and even cause more water to be excreted via your guts, thus upsetting your hydration balance. Try to have these foods and drinks in moderation. 

Prepared by Kara Vogt – Accredited Practicing Dietitian