Posted on 21/11/2022
Do you consume enough water? And how much do you really need each day anyway? And can you consume too much water?
These questions often come up with our patients and within the general media, so here is our take on the issue based upon high quality information from responsible sources we trust.
How much water should I consume each day?
We’re often told that we should be aiming to consume 2.5 litres of water per day, but is that really true?
The 2.5L/day figure was the amount recommended by the U.S. National Academy of Sciences Food and Nutrition Board back in 1945, and it is a figure that still gets put forward today by a number of contemporary and reputable people, including nutritionists Jane Clark and Rosemary Stanton, and exercise guru Joe Wicks. Clark and Stanton do point out that we get plenty of fluid intake in our foods (particularly if we’re eating plenty of vegetables), but nonetheless the 2.5L/day recommendation seems to have become firmly embedded in conventional wisdom. But we’re not so sure about that recommendation, so read on…
Can a ‘one size fits all’ recommendation ever really be truly valid?
Does someone living in a hot climate have the same requirements as someone living in a temperate one? And does someone exercising an hour or two a day have the same requirements as someone who does not? And have you ever tried to actually drink this amount of water each day? It’s not as easy as it sounds, as it is essentially the equivalent of consuming 4 pint glasses of water a day.
These are just some of the reasons why I’m not convinced that blanket recommendations to consume 2.5 litres of water a day are necessary or correct, and the folks from the NHS tend to agree with me.
So how much water should we generally try to aim to consume each day?
Well, as a general guide only, I tend to agree with the thoughts of Dr Rangan Chatterjee, writing in his book ‘The 4 Pillar Plan’:
“In America they have been recommending eight eight ounce glasses of water every day for a number of years. This equates to about 1.9L. This does appear to be quite a lot, and I’m not necessarily sure we all need to be chugging down as much as that. In the U.K. though our glasses are a bit smaller. When we have eight glasses we are looking at about 1.2L of water, which is probably much closer to a practical ideal.”
Or, in other words, about 2 pint glasses of water a day.
So is there absolute science either way?
Like many debates in health care, not really, but perhaps one of the best guides you have regarding your own personal level of hydration at any given time is the colour of your urine. If it is dark yellow and smelly you’re probably dehydrated, whereas a light yellow to clear colour is really what you’re aiming for.
So, in general, we would say aim to consume about 1.2L of water a day, preferably spread out over the course of the day in manageable quantities, and keep an eye on the colour of your urine. If it’s dark and smelly increase your volume of water intake somewhat, but if it’s pale and clear then you’re probably good to go (excuse the pun!).
Bodyfoods For Busy People – Jane Clarke, Quadrille Publishing, 2003.
Healthy Cooking – Rosemary Stanton, Murdoch Books, 1998.
The Fat Loss Plan – Joe Wicks, Pan Macmillan, 2017.
The Four Pillar Plan – Rangan Chatterjee, Penguin Books, 2018.
Waterlogged – Tim Noakes, Human Kinetics, 2012.