Last month, I spent a couple of vacation weeks in Europe. I saw the sights. Perhaps the highlight of my trip was a visit to the real Oktoberfest in Munich, Germany, where many a beer was joyfully imbibed while standing on top of the picnic-style benches singing John Denver’s “Take Me Home, Country Roads.” (The Germans love American singalongs and West Virginia.)
But I’ll argue that it was good — nay, even necessary — to drink so much beer. How else was I going to get hydrated?
You see, Europeans do not share Americans’ love for universally available water. Nary a drinking fountain was to be found overseas. When sitting down to eat at restaurants, water is never served without request. Even purchasable water bottles come in smaller sizes.
This was even the topic of a viral TikTok discussion this July, summed up by the phrase “Europeans don’t believe in water.” Europeans fought back, though, noting that the typical experience of living in the continent isn’t the same as the tourist’s. As “Bon Appetit” noted, “‘Water is basically all we drink round here, but usually sparkling,’ wrote one well-intentioned commenter.”
This whole dichotomy raises significant water questions: Do Americans really drink more water than Europeans? How much water should a person drink? What are the consequences of good or bad hydration? It’s actually a really interesting question for Utahns, especially given our many fitness fans. Let’s dig in.
Water consumption data
Unfortunately, hydration is actually not an incredibly well-studied topic. There’s a real deficit of double-blinded, control-group studies with large sample sizes. Some studies exist that are sponsored by beverage companies like Gatorade, which doesn’t shout “bias-free research.”
There’s also a measurement problem. Measuring hydration is hard. It’s certainly possible (but annoying) to measure liquid intake and urine output. But that misses a significant portion of the human water cycle: The food we eat contributes water, and we sweat a decent amount of it out. Urine color can be an indicator, but may point more to a person’s very recent amount of water consumed rather than the true state of hydration.
Still, we know a little. In particular, we know there is an absolutely gigantic gap between how much water Americans and Europeans actually drink. One journal article from three leading American nutrition researchers entitled “Water, Hydration, and Health” summed up the current state of affairs: “Results of the studies suggest that U.S. adults consume over 2.1 liters of water per day while adults in Europe consume less than half a liter.” Holy cow!
Europeans do, though, tend to drink a lot of non-water beverages to help make up the difference — both alcoholic and non-alcoholic. Numbers are pretty variable depending on the country — adults in the Czech Republic tend to average about a half-liter of alcoholic beverage per day and only a 10th of a liter of non-alcoholic beverages, while adults in the Netherlands drink about a quarter liter of alcohol, but more than a liter in non-alcohol.
As one study noted, “In Hungary, very low total fluid intakes (559 mL) were noted.” They didn’t name their country “Thirsty” for a reason.
Congratulations, you’ve now read the worst joke ever written.
Even taking into account the European preference for non-water beverages that also contain water, Americans are simply significantly better hydrated. The average German, for example, would be in the fifth to 10th percentile among Americans in overall water intake.
(Leah Hogsten | The Salt Lake Tribune) Does drinking beer count when measuring total daily intake of water? In comparing European and American hydration habits, Tribune data columnist Andy Larsen says...somewhat.
How much water do we need?
So is the average German just living through constant dehydration? Not really. In fact, when 24-hour urine samples from a representative group of over 2,000 Germans were studied over the course of 24 hours, only 3% of them were found to be in a state of dehydration. Given how much larger American water diets tend to be, nearly everyone is probably in pretty good shape.
But wait, Andy! Even a cursory Google of “how much water should I drink” will likely come up with the recommendation of the U.S. National Academies of Sciences, Engineering, and Medicine (NASEM). Its recommendation of adequate water intake is a whopping 15.5 cups (3.7 liters) of fluids a day for men, and 11.5 cups (2.7 liters) of fluids a day for women. By these standards, a whole lot of Americans are falling well short of their daily dose of water.
So what explains what’s going on? Well, it turns out the the NASEM’s estimate isn’t based on much at all. In particular, nearly every American they studied was in a state of good hydration, no matter if they were at the top end, middle or bottom end of water consumption in the study. Given that, the agency did a weird thing by setting the recommended water intake to the median intake of the sample. If anything, researchers should have learned that even a lower amount of water intake is fine.
This is the kind of thing that happens when the studies available on a topic are limited — which has been a recent theme in these data articles. Whether it’s sunscreen, or handwashing or water consumption, we tend to not have great data on these very universal topics of improved day-to-day health.
In the absence of solid data, folklore, myth and TikTok wisdom abound: People plugging water fasts, chugging from giant water bottles on Zoom meetings and basically guessing the best amount of hydration.
I will say that I think the German recommendation estimate is a bit more reasonable, about 9 cups of fluid intake per day. After all, they were able to find some actually dehydrated people in their survey.
The impact of exercise
But that default also reflects a relatively normal amount of exertion. Exercise can change the game.
In particular, water losses through the skin can range significantly, from nearly negligible to a whopping two liters per hour in high activity in heat. That really can lead to dehydration quickly, with a resulting rise in core body temperature.
Clearly, dehydration in these settings leads to decreased performances — more so in high-intensity, endurance activities like tennis or long-distance running, with lesser impacts in shorter energetic burst activities like weight-lifting. Research also shows that drinking just to satisfy thirst in these situations usually doesn’t result in rehydration, which means mild dehydration can last for hours after physical activity.
There’s also some correlative evidence that dehydration after exercise can lead to short-term mental impacts, like loss of concentration, alertness, and short-term memory. But other studies showed that water deprivation over the course of 24 hours didn’t see any decrease in cognitive performance — in other words, cognitive decreases may be less about hydration than other consequences of exercise, like body temperature.
There are a few other studied impacts of hydration to be aware of: heart, kidney, and gastrointestinal function, and avoiding headache. On the other hand, there’s not much evidence of hydration’s impact on skin health.
Overall, though, there’s not much data that recommends the average American’s preferred approach to water intake than the average European’s. I’ll admit that I missed my usual water intake when traveling abroad, but found that I got used to the situation after a couple of weeks — and didn’t find myself worse for wear. Quenching your thirst is key, and so too is rehydrating after exercise, but forcing gallons of water down your gullet probably doesn’t need to be a priority.
Andy Larsen is a data columnist for The Salt Lake Tribune. You can reach him at alarsen@sltrib.com
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