Contributed by PWC integrative dietitian nutritionist Jena Savadsky Griffith, RDN, IHC

Besides oxygen, water is our most essential nutrient for survival. We can go for weeks without food, but less time without water. Up to 60% of the human adult body is comprised of water, with the brain and heart composed of 73% water, lungs at 83%, skin at 64%, muscles and kidneys at 79%, and even the bones have about 31% water. Although improving, research shows up to 75% of the population may be dehydrated, with our elderly population particularly at risk.

The most frequent generalized recommendation when it comes to water is to drink 6-8 glasses of water daily. How many times have we heard this since birth? It appears this advice comes more from repetition over the years as opposed to an evidence basis. Scientific endorsement of a minimal water requirement was published in 1945 from the Food & Nutrition Board of the National Academy of Sciences, and it was based on the average amount of calories an adult male would consume. Other US and worldwide agencies adopted similar recommendations using liters, anywhere from 2.0 liters for women to 3.5 liters/day for males (1 liter = 4 glasses). It is now assumed that these recommendations include liquids from all sources, fruits, vegetables, soups and other foods and other liquids including teas, juices, milks, etc.

What Do Recommendations Mean for You?

It’s important to remember that recommendations are just a guide and in many cases are averages taken from a population. Each day and each hour, your body has different needs. Not only does it depend on the climate, season and environment, true hydration depends on your current health status, activity level, diet, weight, sleep quality, medications, stress level, electrolyte balance etc. Hydration is best done slowly throughout the day. Start earlier and if you’re prone to get up in the middle of the night, then you can end earlier. If it’s late afternoon and you try to chug two liters of water at once, it will fill you up and dilute your urine but it may not get into the cells where it is needed. The most important factor is to know what true thirst is for YOU and not attempt to arbitrarily hit a certain number by the end of the day. If you have not felt the thirst sensation in some time, then sipping small amounts of lukewarm water frequently throughout the day for two weeks often helps to awaken these senses.  

Is Plain Water Best?

A recent study tested 13 common beverages to see how they impacted hydration, and you may be surprised to discover that plain water was close to the bottom of the list!  On the other hand, the study told us what we already know: that fluids with electrolytes or minerals like sodium, potassium and magnesium, contribute to better hydration. Further, concentrated colas and fruit juices may provide some hydration at the start, but they eventually cause dehydration because they pull water from the body to dilute the sugars.  These beverages are also filled with extra calories that won’t fill you as well as food.

So how do we translate these results into better hydration for you? Importantly, water is essential for health and, most of us are lucky to have access. It’s best to always bring water from home and only resort to plastic bottles when options are limited, for health and the environment. Importantly, you can easily upgrade your hydration potential without resorting to expensive powders and concentrated sports drinks with the following suggestions:

10 Ways to Increase Cellular Hydration

  1. Add a pinch of sea salt or Himalayan salt.
  2. Add squeezes or slices of lemon, lime, orange.
  3. Add an ounce or two of cranberry, grape or cherry juice.
  4. Increase fruit consumption for cooling and hydration.
  5. Add a half teaspoon of apple cider vinegar.
  6. Drink in between meals to preserve digestive enzymes.
  7. Add mint, cucumber slices or experiment with other plants/herbs.
  8. Use stainless steel bottles, bring water from home, avoid plastic when possible.
  9. Increase teas, broths, soups.
  10. All foods and fluids contribute to water intake!

If constantly thirsty, please consult with a health practitioner as it may be an indicator of an electrolyte balance or other potential health issue.


US Dept. of the Interior. USGS: Science for a changing world. The water in you: Water and the human body. Accessed at:

Australian and New Zealand Journal of Public Health, 2012 vol. 36, no. 3. Accessed at:

The American Journal of Clinical Nutrition, Volume 103, Issue 3, March 2016, Pages 717–723,