Do You Really Need to Drink More Water?
You can eat well and exercise well, but in order to emphasize your identity as a person making healthy choices, you may feel like you need to drain a large bottle several times a day. The benefits of H 2 O rumbling are myriad and legendary , but are they real?
It seems like every week someone comes up with a new gadget or app to keep track of how much water you drink (and encourage you to drink more). Drinking as much water as possible is a simple and powerful thing, but we know that focusing on small, simple changes can backfire if they detract from the meaningful improvements you want to make in your life.
If keeping track of the water keeps you motivated to make other changes and you don’t feel like it’s draining your willpower , go ahead: a few extra glasses a day won’t hurt. But if you scold yourself every day for missing the “water goal,” let’s see when water matters and when it doesn’t.
What does water do
Here’s the worst case for drinking more water: we’re 75% water, or maybe 45% , or somewhere in between. (The exact amount depends on body fat and other factors.) Undoubtedly, water aids blood flow, lubricates joints and other tissues, and is essential for many of the chemical reactions that keep us alive. As you approach the molecular level, water is critical to maintaining the shape of our proteins and membranes. We are water-based creatures. No doubt about it.
But this does not mean that the more the better. As onegroup of dermatologistswrote :
If this logic were applied to gasoline and cars, the reasoning would be this: since gasoline is necessary for a car to function, we need to keep a large amount of gasoline in our car’s tank, and the more the better.
It is clear that running out of gasoline is bad. The loss of significant amounts of water in the body can lead to consequences ranging from headaches and nausea to, in extreme cases, kidney failure and death. Losing a little can cause bad breath and dry skin. But are you dehydrated right now? Probably no.
No epidemic of dehydration
Most of us are already getting over eight glasses a day (although, as we discussed earlier, eight glasses is not a magic number). You may not feel like you are getting that much if you use strict accounting that only includes water, but when it comes to hydration, your body doesn’t know the difference between the water you drink and the water you get elsewhere.
We eat about half of our daily water intake: watermelon and soup are over 90% water, you might have guessed, but even a cheeseburger is 42% . We also get water from other drinks like sodas and coffee,even if they contain caffeine . (Although caffeine can act as a diuretic , your body will adapt to this effect over time.)
In the meantime, remember that sometimes it’s okay to be thirsty and doesn’t mean you are dehydrated : thirst appears at about 2% of your body’s water loss, but you are not medically dehydrated until you feel dehydrated. lost about 5%. (Likewise, as fun as it may be to match your urine to color charts, medium to dark yellow urine is still in the normal range .)
What is water for (and cannot)
Once you have normal hydration levels, the myriad benefits of water begin to fade away. It’s still a great drink choice, but in many cases, the actual health effects don’t match the hype.
Weight loss
There is no evidence that drinking water throughout the day promotes weight loss, but water may be strategic in at least one way: replacing it with high-calorie drinks with meals. A review of the effects of water on weight loss published in Nutrition Reviews found such an exchange to be “promising,” but more research is needed to find out if it works well as a long-term strategy or if we end up compensating for lost calories elsewhere in our days.
Do you feel full from the water? Research on this issue is contradictory, with many studies on both sides. The latter, published in Obesity , is on the yes side. Drinking water before meals seemed to help them lose weight in the short term: people who drank water lost an average of about three pounds in three months. However, there were many variations, some of the subjects even gained weight, so this is not the final conclusion.
Skin health
If you pinch dehydrated skin on a person, it will not immediately snap into place. But does this mean that additional hydration will make your skin look even more youthful and vibrant? This is the logic behind claims that drinking water is good for the skin, but a review published in Clinics in Dermatology found no conclusive evidence for this idea. In one study, drinking an additional two liters of water per day resulted in skin changes that could be measured in the laboratory, but without noticeable improvement in skin roughness or wrinkles.
Brain function
Is mild dehydration preventing your brain from working at its best? The answer is unequivocal: ” yes, but . “ Yes, dehydration in people changes their mood and worsens their test scores, but compelling research done here dehydrates people by making them run on treadmills or sweat water out of their bodies in hot weather, as a Nutrition Reviews review points out. This means the effects may be related to exercise or mild heat illness rather than dehydration. The water pressure for thirsty examiners gave conflicting results: sometimes their grades went up, sometimes they went down. And again, there is no evidence that if you are already hydrated, more water will improve anything.
Organ function
Another common claim is that drinking water helps to “flush out toxins” from the body, but by now we know that you don’t have to do anything special to detoxify : we are not full of toxins, and the few we encounter are taken from taking care of the normal functioning of our organs.
But it is in organ function that we find the real winner:kidney and bladder stones are the only medical conditions that are clearly associated with low water intake over time . This finding is based on a (different)review in Nutrition Reviews thatlooked at the long-term health effects of dehydration. If you are prone to kidney stones, you should definitely drink more water. Much more water . Drink this.
Athletic performance
Here we come to a serious controversy: there are two schools of thought about how much water you should drink during exercise, and both have positive sides.
First, the basics: you need more water if you exercise than if you just sit around. Since you lose water through sweating, exercise intensity and ambient temperature are important (you need more water flowing in a hot day than walking on a cold day). But how much is enough and how much is too much?
There is a rule of thumb that mild dehydration – as little as 2% of your body weight – can affect your performance (like slowing down in a race or feeling unwell during exercise), but areview of recent Research from the British Journal of Sports Medicine. showed that in real conditions the performance of athletes does not suffer until they lose at least 4%. (This would be a 6 pound loss for a 150 pound person, or quite a lot in other words.) In fact, mild dehydration can improve performance in some cases (and no, it doesn’t cause cramping ).
Most of us would prefer to stay hydrated just in case. The question then becomes whether this means that we should drink as much water as possible before, during and after exercise; or whether to drink enough when thirsty.
Here is the disagreement. The American College of Sports Medicine has issued a guideline that recommends tracking and measuring fluid intake; they provide estimates and suggest that you monitor your weight before and after exercise to determine if you are drinking enough. “By itself, the thirst – not the best indicator … the body needs fluid,” – said in a statement .
This was in response to a competing set of IOM guidelines , which clearly state: “The vast majority of healthy people adequately meet their daily fluid needs, allowing thirst to be their guide.” The sports scientists at this camp are concerned that fear of dehydration has led too many people to drink too much , which could lead to their own set of health problems (including potentially fatal complications ).
The latest consensus statement on overhydration concludes that athletes should drink before thirst , except in extreme situations, such as a marathon on a hot day, when a little preventive drinking may be required.
Water is beautiful, but don’t waste your willpower
While it is okay to drink too much water, it is only possible if you drink liter by liter (as some people do during exercise when they are told to drink fluids). For everyday purposes, it doesn’t hurt to drink a few extra glasses a day. Just don’t worry about how much you drink, don’t worry about tracking every drop of water, and don’t worry about dehydration if you don’t really feel it.
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