Do I Really Need to Drink 8 Glasses of Water Each Day?

Published by jay on

drinking water

One hears it everywhere: drink eight 8-ounce glasses of water a day. But just where did that idea come from, and is it really necessary for good health?

Water is a very important component of a healthily functioning body, no doubt about it. But when it comes to just how much water one should drink on a daily basis, it’s a little bit harder to find an answer. In recent years, the rule of 64 ounces (or eight 8-ounce glasses) of water each day, has become the accepted standard, but research has proven that claim is not necessarily as solid as some have been led to believe.

The Origin of Eight Glasses a Day

drinking water

While there is no concrete evidence supporting just where this idea first came from, many people believe that the trend stemmed from a statement made by the Food and Nutrition Board of the National Research Council in 1945.

The Board recommended one milliliter of water for each calorie of food, which equals roughly 64-80 ounces. However, what many people fail to realize about this recommendation is that the amount is for total water intake, including what one may obtain from foods and other beverages.

Other Sources of Water

Water can be obtained from a variety of other sources and contribute to the daily recommended liquid intake. Contrary to popular belief that caffeinated drinks dehydrate, individuals who are used to drinking caffeine can receive water from caffeinated beverages such as soda, tea, and coffee. Water can also be obtained from juice, milk, and even from food. Water rich foods can provide up to 20% of the body’s daily need of water.

How Much Water Does the Body Need?

drinking water

So, if a portion of one’s daily water needs can be obtained from drinking juice, tea, and from food, then just how much water does one need to drink on a daily basis? There really is no magic number that applies across the board. Just as daily calorie needs vary due to activity level, age, and other factors, the daily water intake varies as well. The amount may be higher for individuals who live in warmer, drier climates, are more physically active, or suffer from certain health conditions, while those whose daily activity level is lower may not need to drink quite as much water.

The general rule is that one should take in enough water to replace what is lost every day through perspiration and other bodily functions. According to the Mayo Clinic, that number is somewhere around 10 cups of water. Replenishing that loss can come from pure water, other beverages, and foods, and may be higher or lower depending on the individual.

So when striving to keep the body hydrated, keep in mind the fact that 64 ounces of water is simply a rule of thumb amount, not a rigid standard. There is no conclusive evidence that drinking 64 ounces of water a day results in better health. While it is extremely important to keep the body properly hydrated, listening to ones own body, taking into account personal activity levels, and keeping track of the amount of water received from other sources can be more effective for proper hydration than following the 8-glass standard.