glass of water on table

Eight glasses a day – myth or magic

Posted  April 6, 2016

Water is essential for life. That is a given. However, it’s not quite as clear how much water is needed for the average human being to enjoy optimal health. The old “eight glasses a day” guideline has mostly been dismissed as a myth, but no helpful rule of thumb has emerged in its place.

We took a look at the guidelines for water consumption and the different circumstances in which you might need to drink more or less, to help you to get a handle on your daily drinking habits.

Why is water so important?The human body is made up of about 60% water, and the liquid is essential for every organ and bodily function – for instance, digestion, circulation, transportation of nutrients and regulation of temperature. But we are also constantly losing water through various bodily functions. For this reason, we have to replenish our water levels all the time.

What happens if we don’t get enough water?People who don’t drink enough water every day are more susceptible to a host of ailments, some of which simply cause discomfort, while others can contribute to other health complications. These ailments include muscle cramps, dry skin, chills, mood swings, headaches, impaired concentration, bad breath, fatigue, dizziness, dark urine, urinary tract infections and constipation.

Why do they recommend eight glasses? According to paediatrician Aaron E Carroll, who debunks medical myths, the source of the “8 glasses of water a day” guideline is a 1945 USA Food and Nutrition Board recommendation that stated that people need around 2.5 litres of water a day. But the myth ignores the next part of the statement, which read, “Most of this quantity is contained in prepared foods.”

Yes, the human body is fairly efficient at extracting water from food, and especially from fruit and vegetables. And despite what you hear about caffeinated and sugary drinks dehydrating you, this is not a scientific fact and these beverages also contribute to your daily water intake. Of course, however, actual water remains the best source of water, simply because you aren’t adding anything else to your body that will need to be processed and flushed out.

So how much water is actually enough?
While it’s important to understand that it’s possible to be healthy and even flourish on less than eight glasses a day, there’s no harm in drinking that many. So in the absence of another guideline or a simple way of calculating your body’s specific needs, eight glasses is as good a rule of thumb as any. But don’t worry if you drink a little less – remember, you are still hydrating from other sources as well – so if you’ve just enjoyed a big bowl of watermelon, you’ve probably met your short-term hydration needs.

emember also that when your body lets you know it’s thirsty, you are already in the early stages of dehydration. Rather than waiting until that point to have a drink, try to work out a water drinking schedule that keeps you regularly hydrated and thirst-free throughout the day. Eight glasses will certainly do that for you.

When you might need to up your water intakeOf course, there are circumstances under which you might need to drink a bit – or a lot – more to replace water that you are losing. For example, you will need to drink more when it is extremely hot, when you are being active or when you are ill – especially with an illness like stomach flu that directly causes fluid loss.

Extreme fluid loss brought on by intense physical activity or extended illness should also be treated with an electrolyte solution, as many of the vital minerals in your body will also have been lost.

How to make drinking water a habit One of the common reasons that people give for not drinking enough is that they simply don’t remember. To stay hydrated and healthy, try to introduce reminders into your life that will help you to drink more. You can always drink a glass of water before each meal (which also helps reduce overeating). You could try carrying a two-litre bottle of water with you for easy access and a visual reminder all day. When you get a glass of water from the kitchen or water cooler, drink one glass while you stand there, then carry another glass back to your desk to sip. If you drink tea, coffee or fizzy drinks, drink a glass of water first. And if you go to a restaurant, order water rather than a fizzy drink, coffee or alcoholic beverage.

Bottoms up! The simple truth is that eight isn’t a magic number for water consumption. But the fact that water is good for you is no myth, so for good health and happiness, set yourself a water drinking goal and stick to it, using whatever method works for you. Magic or not, water will do you wonders.

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