Top tip: Drink 8 glasses of non-alcholic drinks a every day. This really helps with fluid retention by ridding the body of sodium, and keeps you full. Slight dehydration really affects your concentration and food cravings can often be a sign of dehydration. There's also a link between poor hydration and cancers of the colon, urinary tract and breast.

83 per cent of blood is made up of water
75 per cent of lean muscle (including brain tissue) is water
25 per cent of fat is water
22 per cent of those solid-looking bones are water.