Intended for healthcare professionals

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Feature Health Marketing


BMJ 2011; 343 doi: (Published 12 July 2011) Cite this as: BMJ 2011;343:d4280

Rapid Response:

Misleading and unhelpful

Dr McCartney's opinion piece seems to be dismissing the years of
research by scientists in this country and across Europe. This kind of
article is misleading and unhelpful. UK government guidelines advise
drinking 6-8 glasses of fluid per day (as opposed to water alone) to stop
us getting dehydrated(1).

For a healthy person a 1 to 2% reduction in body weight over the day
can signal mild dehydration and reduce our ability to concentrate.
Dehydration can leave us feeling tired, dizzy and suffering from
headaches(2). The NHS advises that 'water is the healthiest choice for
quenching your thirst at any time'(3).

Over-hydration is very rare and usually only occurs when large
amounts of water are consumed over a short period of time but not when
spread over the day.

As highlighted by a report in The Lancet in August the obesity crisis
in the UK and across the globe is getting worse. Weight gain is caused by
an excess in calories we eat, and calories we burn off in physical
activity. Children aged 4-10 get about one-fifth of their sugar intake
from soft and sugar sweetened drinks and those aged 11-18 get about one-
third of their sugar intake from soft and sugar sweetened drinks(4). In
fact the average Briton drinks just 200ml of water a day - equivalent of
less than one glass(5).

Drinking water is one of the best ways to hydrate and contains zero
sugar, calories, preservatives or additives. So when the country is facing
an obesity crisis it's not helpful to denigrate water.


(1)NHS Choices:

(2)Mayo Clinic (2008) Dehydration Symptoms:

(3)NHS Choices:

(4)NHS Choices

(5)DEFRA National Tap Water Consumption Survey 2008

Competing interests: No competing interests

05 September 2011
Kinvara Carey
General Manager
Natural Hydration Council