Most people would know that the recommended fluid intake is 1.5 to 2 litres or 6-8 glasses.
The NHS, although quoting the Eatwell Guide as well, suggests that we drink “plenty of water”. But how much is ‘plenty’? Is there, perhaps, an upper limit?
In 2007, a 59-year-old woman nearly died after drinking too much water. Incidents like this are sporadic, but it happens occasionally and shows that even water can be detrimental if over consumed.
In reality, many people struggle to drink the recommended 6-8 glasses per day. In 2002, researcher Heinz Valtin went in search of the source of this often-quoted recommendation. He was unable to find it. There is no scientific evidence for the advice to drink 6-8 glasses per day.
The absence of evidence is not surprising, considering that the water requirement changes from person to person and from day to day.
How much you need to drink depends on your gender, age, weight, activity level, climate, altitude, medication etc….