The importance of water to our bodies cannot be underestimated, and it's no coincidence that it makes up about two-thirds of the weight of a healthy body. Most of the chemical reactions that happen in the cells in our body need water in order to take place, and we also need it so that our blood can carry nutrients around the body and get rid of waste. But how much water should we drink? We lose fluid through our sweat, urinate and breathe and it's essential that we replace it; and we while we get some fluid from our food most of it comes from drinks. The European Food Safety Authority recommends that women should drink about 1.6 litres of fluid and men should drink about 2.0 litres of fluid per day. That's about eight 200ml glasses for a woman and 10 200ml glasses for a man. However, the amount a person needs to drink to avoid getting dehydrated will vary depending on a range of factors including their size, the temperature and how active they are. So it goes without saying that if you're exercising hard in hot weather you'll need to drink more. All drinks count, including hot drinks such as tea and coffee, but water, milk and fruit juices are the healthiest; and it is wise to avoid alcoholic drinks. Try to avoid sugary, soft and fizzy drinks that can be high in added sugars as these can be high in calories and bad for your teeth.