How much water do we need in a day

You need to drink eight glasses of water a day

How many of us can think of a time where we were told by someone in our life that if we wanted to be healthy we had to drink eight glasses of water a day?

Did you ever stop to think where this magical number eight originated from?

We all know that drinking water is necessary to sustain life. Most of our body is made up of water and without it, we wouldn’t be able to survive. A few key health benefits of drinking water include:

• it carries nutrients and oxygen to your cells
• flushes bacteria from your bladder
• aides in digestion
• prevents constipation
• cushions our joints and
• protects our organs and tissues

How much water do we really need–Debunking the “magic eight” myth

Water is a requirement for human life- there is no arguing that. However, the amount of water we actually need is a highly debated and researched topic. Each day we consume water and expel water. The amount of water we consume and expel is highly individualized and differs from person to person. This individualized variation makes it very difficult to formulate an exact recommendation for the entire population.

Let’s look at the Media claims, shall we?

This video clip is meant to be a motivator to viewers in order to achieve the recommended eight glasses of water a day. It begins by saying that we all know we need to be drinking eight glasses of water a day, but do we really know this? Or are we simply following recommendations with no logistical evidence? In fact, a 2008 publication issued by the Journal of the American Society of Nephrology found that there is no clear evidence to indicate that any health benefit comes from drinking eight glasses of water a day (Lunn & Foxen, 2008). Water is tricky because there is such a thing as consuming too much and too little. Too little leads to dehydration and too much can lead to water intoxication. We excrete water through sweating and our kidneys.

Individuals excrete different amounts of water through sweat because of the fact that we all sweat at different rates. The reason it is so difficult to set a standard for the amount of water each person needs to consume is that requirements vary massively depending on environmental temperatures, humidity, and physical activity. Suggesting everyone consume eight glasses of water a day is simplifying a very complex issue (Lunn & Foxen, 2008).T

This video clip again suggests we should drink the recommended eight glasses of eight ounces of water a day for a total of 64 ounces. When considering the recommendations set forth to drink eight glasses of water a day, there is not enough specification. Consider the following:

• Are we talking strictly water or are we including fluids that contain electrolytes such as Gatorade?
• Is this inclusive to various climates, ages, physical activity levels?

It is hard to imagine that a sedentary person who sits on the couch, and an athlete, or a marathon runner, will require the exact same amount of water a day. Not to mention special circumstances such as sickness, or how a hike in a desert climate will alter the total amount of fluids needed. Research into this phenomenon has proved that there is little to NO scientific evidence supporting the claims that eight glasses of water a day is sufficient for all people (Valtin, 2002).

There are also claims that drinking eight glasses of water day correlates to weight loss and health improvements. Again, there is no scientific evidence to support these claims, however, drinking a glass of water while eating will lead to the feeling of being full which can, in turn, lead to us eating less. This is potentially where the belief began that eight glasses of water a day improves health and weight loss (Valtin, 2002).

Finally, it is suggested that it helps with constipation. Research has shown that increased fluids leads to more urine expulsion but has not been associated with the facilitation of bowel movements. Despite extensive searches of the literature and discussions with nutritionists, this author could confidently say he found no scientific reports concluding that we all must drink at least eight glasses of water a day. He goes on to say that the recommendations could actually be harmful (Valtin, 2002).

This final media clip gives eight ways to make sure you drink the recommended eight glasses of water a day. This included setting eight alarms a day and drinking a full eight ounces of water every time it went off, and wearing eight rubber bands on your wrist and taking one off with each glass that was consumed.

Once again, it is recognized that the classic recommendation is eight glasses of eight oz of liquid per day—not including caffeinated and alcoholic beverages. Through years and years of thorough research, scientists have concluded that they cannot find the exact origin of this theory. There is no single study and no single outcome that has led back to these recommendations (Negoianu & Goldfarb, 2008).

Ultimately, there is no clear evidence of any benefits from drinking increased amounts of water. Nonetheless, there is also no clear lack of benefit. There is simply a lack of evidence in general. It all boils down to the fact that water intake is extremely individualized based on a variety of factors and it will be difficult, maybe even impossible, to ever get a standardized recommendation across all persons in all places (Negoianu & Goldfarb, 2008).

In summary, research has busted the myth of needing to drink eight glasses of water a day. It turns out, the amount of water we need is highly individualized. It is dependent on physical activity level, age, climate, state of health, and the amount we sweat to name a few. As a general rule of thumb individuals should try to consume roughly 2 liters of fluid a day between water and food.

References

Lunn, J., & Foxen, R. (2008). How much water do we really need? British Nutrition Foundation Nutrition Bulletin, 33(1), 336–342.

Negoianu, D. & Goldfarb, S. (2008). Just add water. J Am Soc Nephrol 19(1), 1041-1043.

Valtin, H. (2002). Drink at least eight glasses of water a day. really? is there scientific evidence for 8 x 8? Am J Physiol Regul Integr Comp Physiol, 283(1), 993-1004.