Water balance & liquid requirement

 Our body loses between 1.8 and 2.3 litres of water per day as a result of breathing, through the skin and due to excretion. This quantity needs to be replenished. A poor water balance means that our body cannot function to the best of its ability. This triggers the sensation of thirst, an alarm bell rung by the body when the water balance drops by just 0.5 percent.

 Our physical and mental capacity begins to suffer as soon as our water balance reaches minus 2 percent. Fluid loss of more than 10 percent leads to mental confusion. Losing 20 percent or more leads to kidney and cardiovascular failure - which will ultimately end in death.

 The loss of liquid must be replenished as a matter of urgency. We replenish liquid every day when we ingest solid food, albeit to a certain extent. However, drinks should represent at least 1.5 litres of our daily liquid requirements.


This figure is to be taken as a recommended quantity. A person's liquid requirements depend on many factors, including age and physical exertion. To make sure that we do not upset our body's liquid balance, it is extremely important to drink at regular intervals throughout the day.






Useful drinking advice


  • Drink at least 1.5 litres daily – ideally water. Water quenches the thirst best – without any calories.


  • When it is hot outside and when undertaking sports activities or physical work, the water requirement is two to three times higher.


  • Thirst signals that the body lacks fluid. Therefore drink regularly, before you get thirsty.