How much water should you really drink every day? This deceptively simple question has been hotly debated among nutritionists, scientists and doctors, alike. And current opinions are just as divided as they were 20 years ago. But now we appear to have a definitive answer…
A vexed question…
Over the past several decades, various ‘authorities’ have floated widely varying recommendations for how much water the average adult should drink each day to maintain proper hydration.
Current numbers range from 48 oz. / 1.5 L (six 8 oz. glasses) to 128 oz. / 3.8 L (16 glasses). One national nutrition guide, published late in the last century, infamously told its country’s population to drink ‘at least 10 glasses’ (80 fl. oz. / 2.4 L) of water a day.
The only time I every managed to do that was during bowl prep for my latest colonoscopy. Drink that much, and you’re really floating! You’ll urinate 6 to 8 (or more) times a day, and have to get up multiple times overnight. And that sort of regimen will definitely interfere with your accustomed daily routine. I can’t imagine how I’d cope with 16 glasses a day!
A unified stand?
Alas, no. A survey of current official recommendations reveals an even broader range of disagreement…
Highly respected Harvard Medical School comes in lowest, at 4 to 6 glasses per day.
In Canada, for example, My Health Alberta echoes the national recommendation: 6 to 8 glasses per day. And that’s in line with the current mean of 8 to 10 glasses per day around the world.
On the other end of the continuum, The Mayo Clinic recommends as much as 16 glasses per day for men and 12 glasses a day for women.
Medical News Today cautions: “The commonly touted wisdom of eight glasses of water per day may be suitable for some people, but it is not a ‘one-size-fits-all’ recommendation. […] Some experts say there is a lack of scientific evidence supporting these claims. Others note that [high rate] promoters include bottled water manufacturers.”
An insidious hoax?
No complete discussion of water consumption recommendations should exclude mention of the Great Myth theory…
The University of Michigan Heath System has immortalized this contrarian view: “The human body is beautifully designed to let you know you need to drink long before you are at risk of becoming dehydrated. Drink when you are thirsty. If you are doing strenuous work in a hot environment, you need to drink extra fluid to make up for what you lose through perspiration (sweat).”
A simple check…
“Use the color of your urine as a guide. Your urine should be light yellow. If it looks like water, you are drinking more than you need. If it is dark yellow or orange you need to drink more.”
Further to that point, there are some signs of dehydration everyone in the game seems to agree on:
- Extreme thirst
- Extreme fussiness or sleepiness in infants and children; irritability and confusion in adults
- Very dry mouth, skin and mucous membranes
- Sunken eyes
- Shriveled and dry skin that lacks elasticity and doesn’t ‘bounce back’ when pinched into a fold
My take
The definitive answer to the Great Question of how much water you should drink per day is really a set of rules of thumb. Just as the Great Myth theory holds. We are all different, and we all need our own amount of hydration.
Another victory for common sense!
~ Maggie J.