Dr. Doug Pooley
The Importance of Optimum Fluid Intake
Updated: Jan 19
When people try to rain on your parade, pee on theirs.
To pee or not to pee … is that the question?
It is safe to assume that anyone reading this has at least some appreciation for the importance of water to life. The human body is made up of about eleven gallons (forty-two litres) of water, which accounts for between 50 and 70 percent of body weight. Your blood is 85 percent water, muscles 80 percent water, your brain 75 percent water. Even your bones are 25 percent water. All of this illustrates the important role that water plays in our lives. So, for the most part we are just large moving bags of water. What you may not know is the direct correlation between fluid intake to health, vitality, energy production and weight loss. Water has been known as a key component of well-being for ages, and we all know we must drink it as part of life, but few individuals understand the astounding health implications associated with optimally hydrating the body.
We are going to use water for all its cleansing, energy producing, detoxifying, weight loss and healing properties. It is key to health and wellness and is one of the most overlooked necessities of life and health. In short, when we are thirsty, we know that we must drink. Beyond that, most of us don’t give it much thought.
I did a quick survey of fifty of my patients over the age of fifty-five to get an idea of whether they understood the importance of water to life, and the answers were not as predictable as one would think. I asked them the following nine questions:
Do you believe that water is critical to life and important for clearing waste from the body? yes___ no___
Most people seemed to understand that water is critical to life and very important in clearing waste from the body.
Do you think that water intake levels determine how well we clear waste from the body? yes___ no__ don’t know__
About 30 percent said that they did not know, which was interesting. Approximately 50 percent answered yes to the question, and the remaining 20 percent said no.
Is every bodily function dependent upon water for efficiency? yes___ no___
About 50 percent recognized that every bodily function was dependent upon water, but most admitted that in making “yes” their choice, they were simply making a logical assumption rather than basing the answer upon fact and knowledge.
Is maintaining optimum fluid intake levels more important when you are younger?
yes ___ no___
The right answer was no, and 40 percent of respondents chose the correct answer. Although it is important at every stage of life to hydrate properly, maintaining proper fluid intake when older is more important to health, for reasons I will present a bit later.
Do you think that drinking water can impact weight loss? yes___ no___
Close to 65 percent said “yes,” but upon further questioning, most did not know why.
Can diseases such as type 2 diabetes, heart disease and cancer be impacted by fluid intake levels? yes___ no___ don’t know___
Approximately 60 percent agreed that hydration was related to disease, 30 percent said they did not know, and only 10 percent said no. Again, the interesting thing with this question was that, upon further questioning, many who voted yes did so based upon logic rather than knowledge. Even though this is a small sampling, the answers to this question indicate a knowledge gap.
Do you think that you drink enough water? yes___ no___ don’t know___
Approximately 60 percent thought that they drank enough water, with 20 percent voting no, and approximately 20 percent admitting that they did not know.
How many 8 oz. glasses of water should you drink per day? 4___ 6___ 8___ 10___
This is where it got interesting. The answers were all over the board and evenly distributed between four, six and eight. The responses again gave testament to the fact that many of our targeted audience over the age of fifty-five had little concrete understanding of the subject.
Do you think you would be healthier if you drank more water? yes___ no___
This last question saw about a 70/30 “yes” versus “no” split.
This simple survey demonstrated that the public generally acknowledges the importance of water to health but possesses little understanding as to why. There would be real value in a more structured study to better assess public knowledge of the link between disease and hydration, especially as applied to an ageing population.
As you age, your body’s fluid reserves become smaller. With that your ability to conserve water is reduced and your thirst sense becomes less acute. These problems are compounded by chronic illnesses such as diabetes and dementia, as well as using many medications. Older adults also may have mobility problems that limit their ability to readily obtain water for themselves. People with chronic illnesses such as having poorly controlled or untreated diabetes puts them at high risk of dehydration. Kidney disease also increases your risk, as do medications that increase urination. Older adults commonly become dehydrated during minor illnesses such as influenza, bronchitis, or bladder infections. I am sure that you have noted that even having a cold or sore throat makes you more susceptible to dehydration because you’re less likely to feel like eating or drinking when you’re sick.
I believe firmly that one of the major contributors to the development of chronic disease is because we don’t optimally hydrate our bodies. Dehydration does not have to be severe to contribute to health problems. Even moderate levels of dehydration can create metabolic stress that may lead to ill health.
Even mild dehydration adversely affects cognitive performance and increases fatigue. Some of the common side effects associated with dehydration include low blood pressure, weakness, dizziness, and increased risk of falls. Is this ringing any bells? In an article published on the Cognitive Vitality website, Dr. Betsy Mills notes that “Just a 2% drop in body water levels has the potential to result in a small but impactful shrinkage of the brain, sufficient to impair coordination, decrease concentration, and slow thinking.” If this sounds a lot like some typical signs of getting older, you are right. In a 2013 study published on the Medical Daily website, John Erikson wrote that “[Seventy-five] percent of the American population fall[s] short of the 10 daily cups [of water] prescribed by the Institute of Medicine.” One thing is unequivocal: Dehydration is a more common and serious health concern than most understand, especially among the elderly.
Water is more important to health than you think
Let’s look a little closer at some of the clinical aspects of dehydration along with the health benefits associated with proper fluid consumption, (hydration).
Impacts mood and cognitive function: If you are dehydrated, even mildly, your mood and cognitive function may suffer. In fact, there is significant research demonstrating that the likelihood of making mistakes performing even simple routine tasks increases dramatically the more dehydrated you become. You may be surprised to learn that even seemingly minute levels of dehydration can negatively impact short-term memory, precipitate negative mood changes, and alter concentration and reaction times.
Reduces fatigue: Although water does not provide energy in the same way as carbohydrates and fats do, it plays an important role in energy transformation. Water is the medium through which all energy reactions take place. If you become dehydrated you will become lethargic, may experience cramping, and your endurance and strength performance suffers. Athletes who become dehydrated often experience reduced performance in the days following periods of exercise-induced fluid loss. Mild dehydration is also one of the most common causes of daytime fatigue. The number of my patients who suddenly feel more energetic after doing nothing more than hydrating properly is surprising.
Helps in weight loss: In work published in the journal Frontiers in Nutrition, author Simon N. Thornton found that “Increased water intake is associated with loss of body weight via two mechanisms, decreased feeding and increased lipolysis.” The reverse also appears to be true.  In a Healthline article published in December 2020, Adda Bjarnadottir, a registered nurse, notes, “Studies of older adults have shown that drinking water before each meal may increase weight loss by 2 kg (4.4 lb.) over a 12-week period.”
Water can suppress appetite naturally and increase the body’s ability to metabolize stored fat. Yup! Drinking water can help us lose weight! A study published in the Journal of Clinical and Diagnostic Research in 2013 by Vinu A. Vij and Anjali S Joshi found, “The decrease in body weight, body mass index and body composition scores of overweight subjects at the end of study period establishes the role of water induced thermogenesis in weight reduction of overweight subjects.” In plain English: They lost weight.
As well, water:
Helps us feel full so we potentially consume fewer calories.
Speeds up our metabolism marginally but is a good replacement for other liquid calories.
Flushes out fats and toxins.
Improves bowel function and reduces constipation.
Gets rid of wastes through urination, sweating and bowel movements.
Studies have shown that a decrease in water intake could cause fat deposits to increase. On the other hand, raising the amount of water we consume can reduce levels of fat deposits. This is thought to occur because a reduction in water decreases the efficiency of the kidneys, which results in some kidney functions being shunted to the liver. One of the liver’s primary functions is to metabolize stored fat into usable energy for fuelling the body. Therefore, in a state of dehydration, the liver metabolizes less fat while being forced to perform functions normally taken care of by the kidneys. This results in less stored fat being burned and a reduction in weight loss potential. As mentioned, water is critical in helping our liver convert fat into usable energy.
Reduces fluid retention: Many older people are constantly fighting the bloating associated with fluid retention due to an excess of stored water in their bodies. Surprisingly, failure to drink enough is often a major cause. The body perceives dehydration as a threat to survival, which triggers a series of protective physiological functions. It begins by the body holding on to every drop of available fluid in case rehydration is not imminent. When this happens, water gets stored in extracellular spaces (outside the cell), which can contribute to swollen extremities (feet, legs, and hands).
According to a study by the Centre for Disease Control and Prevention in Atlanta, “Forty-three percent of the North American adult population drink less than four cups of water a day, with seven percent reporting they don’t drink any water at all.” This is a death sentence due to the strain that dehydration levies on the life-supporting systems in the body. As mentioned, if we don’t drink enough, kidney and liver functions can be impacted. These organs can potentially become overwhelmed with concentrated waste and toxins, which could lead to the increases in circulating toxins. Instead of excreting water and waste products, our body further retains existing water to dilute concentrations of toxic metabolic by-products. This is a major contributor to water retention and bloating and is reflected as weight gain. At first blush it may seem a little odd, but one of the best ways to get rid of excess water is to increase water intake and flush out the accumulated toxins.
Helps build muscle: Water transports nutrients such as protein to our cells and removes waste from the body. Water also helps in the synthesis of protein and glycogen, which are critical to muscle metabolism. To move and flex our muscles, we need water. If our body is dehydrated, the muscles will be deprived of electrolytes and cramps will often result. Without the proper water and electrolyte balance, muscle strength and control will also be impaired. It is essential that we stay hydrated if we want to build muscle and experience optimal performance whether in the gym, on the golf course or just puttering around the house.
May be linked to cancer and heart disease: In a study posted in the Journal of Clinical Oncology entitled “Water Intake and Cancer Prevention,” the authors note that there is some compelling research showing a link between higher levels of water intake to a lower risk of certain types of cancer, such as bladder, breast, and colon-rectal cancer.
Even the risk of fatal coronary heart disease has been linked in part to water intake. In a 2019 article published in PubMed by Watso and Farquhar, the authors reveal that “Observational studies have linked habitual low water intake with increased future risk for adverse cardiovascular events. While it is currently unclear how chronic reductions in water intake may predispose individuals to greater future risk for adverse cardiovascular events, there is evidence that acute hypohydration impairs vascular function and blood pressure (BP) regulation.”
Our bodies also need water for blood circulation, various metabolic processes, regulation of body temperature and waste removal, which are all important components of health maintenance and critical to maintaining an ageing body making adequate fluid intake a key component of achieving a state of “super-health.”
 Thornton, Simon N “Increase Hydration can Be Associated with Weight loss.” Published 2016 Journal Frontiers of In Nutrition  Bjarnadottir, Adda MS, RDN. “How Drinking More Water Can Help You Lose Weight”, Healthline article, December 2020.  Vinyl A. Vij and Anjali S. Joshi. “Effects of water induced thermogenesis’ on body weight, body mass index and body composition of overweight subjects”, Journal of Clinical and Diagnostic Research, 2013.  David, Yair Bar, Gesundheit Benjamin et all “Water Intake and Cancer Prevention.” Published 2004 Journal of Clinical Oncology.  Watso and Farquhar. “Hydration Status and Cardiovascular Function”, PubMed,2019.