Why is it important to drink lots of water?

Our bodies need water (and other fluids) to work properly. Water makes up about two-thirds of our body weight - it's important this is maintained because most of the chemical reactions that happen in our cells need water. We also need water for our blood to be able to carry nutrients around the body. Although water is not a nutrient in the classical sense, human beings would be unable to survive without it.

Losing water

We lose water through evaporation when we breathe and sweat. As the temperature rises and as we do more activity, this increases the amount of water the body loses. To stay healthy, we need to replace the fluids that are lost. The body also gets rid of waste products from the body through the kidneys in urine, and urine is mainly made up of water.

How much water do we need?

The amount of water (and other fluids) that we need to drink each day varies from person to person, depending on age, time of year, climatic conditions, diet and the amount of physical activity we do. For instance, we need more water in hot climates and following exercise. We can obtain our fluid requirements from a number of sources other than water, as well as from the food we eat. In climates such as the UK, we should drink approximately 1.2 litres (6 to 8 glasses) of fluid every day to avoid dehydration.