Written by: Scott Robinson, Executive Contributor
Executive Contributors at Brainz Magazine are handpicked and invited to contribute because of their knowledge and valuable insight within their area of expertise.
Do you really need eight glasses of water a day? The mantra that you need eight glasses of water daily has been around for a long time. This recommendation originated from the US National Research Council in 1945. There is, in fact, no scientific validation for this recommendation.
Food as a primary source of water
Most people do not realise that a significant portion of water comes from our daily food. For example, lettuce contains 90 – 99% water; apples contain 80 – 89% water; bananas contain 70– 79% water; salmon has 60 – 69% water etc.
Considering the average daily intake of 2000 calories across various food groups, you will need far less than glasses of water daily.
A method for calculating how much water you should drink
You can also measure the amount of water by this simple calculation. Take your weight (kg) and multiply that by 0.033. A more active person may wish to drink more.
That said, these measures are only estimations. The best way to know how much water you should drink daily is to listen to your body and its subtle signals.
How the body signals thirst
Until recently, the precise mechanism by which the body signals the desire to drink was not known. Recent research shows that the body has the same sensory system as its auditory and visual faculties. The gut, blood and mouth contain nodes that signal to the brain the hydration levels in the body. These signals are a reliable indicator of the body’s actual hydration levels. These signals are sent to the forebrain, determining how much water the body needs. From this, the urge to drink occurs.
Drinking and eating
You will often hear that you should not drink water during a meal. Water ‘dilutes the stomach acid’, so the 'digestive fire' becomes weak.
The physiology of drinking suggests something else. When you eat, it triggers a desire to drink fluid in advance of the proper digestion of the food. The research indicates suppression of eating occurs in the absence of fluid intake. So, drinking whilst eating is a natural process.
The role of swallowing
The physical act of swallowing water acts as a lever for fluid intake. You will notice that the ability to drink seems endless if you feel thirsty. After drinking so much water, the ability to swallow will feel suppressed.
The colour of urine
The colour of your urine is a reliable indicator of the body’s hydration level. The kidneys produce urea and other waste products. These dissolve in water. The darker the yellow urine colour, the more dehydrated you are. Of course, other factors may also contribute to a darker urine colour, such as whether you are taking vitamin supplements.
Conclusion
There is significant confusion about how much water you should drink daily. In particular, that you should drink 8 glasses of water a day. The most reliable indicator is listening to your body and its innate intelligence. The body constantly calculates how much water it needs and will signal the urge to drink. The ability to swallow will gauge the body’s capacity to consume fluid. In other words, let ‘thirst’ be your guide.
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Scott Robinson, Executive Contributor Brainz Magazine
Scott Robinson is a Finance Professional and Yoga Teacher. He is also the founder of Yogibanker ‒ a specialised yoga & wellbeing service for the financial services industry. He helped found 'dbYoga' at Deutsche Bank, one of the world's leading financial services companies as well as leading regular mindfulness sessions under the brand of 'Mindfulness Mondays'. Over the years, Scott has helped hundreds of finance professionals become stronger, more flexible and less stressed through yoga & mindfulness. Scott's passion is to bring yoga & wellbeing to the financial services industry ‒ one that is kinder, more sustainable with wellbeing at its core.