DrG's Medisense Feature Article

How Much Water Is Enough?
by Ann Gerhardt, MD
December 2021
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Especially in winter, when few feel much thirst and we’d really prefer hot chocolate or a steaming mug of apple cider, it can be hard to drink enough water.  Yet, regardless of season, our bodies persist in their mundane, water-dependent metabolism which we often short-change.

Most of us would feel better and be healthier if we drank more water – non-caffeinated, non-caloric, non-alcoholic, non-boosted water.  Hot, cold, flavored, still or carbonated, we need lots of it for health.

Water has profound health benefits.  It maintains normal volume of blood, which is about 67% water.  Adequate blood volume maximizes organ function, particularly that of the kidneys.  It maintains adequate blood pressure, which improves energy and keeps us from passing out when we stand up.  Hydrated skin has fewer scales and wrinkles and lubricated joints hurt less.  Water reduces constipation by softening stool but the body absorbs all it needs for all the above before it allows some to make it to the colon.  Water is necessary for weight loss, since the body needs it to break down fat molecules for energy.

Too many people think they “get enough water” because they are not thirsty, but thirst doesn’t kick in until there is real dehydration.  Or they feel that drinking coffee, tea or soda all day suffices.  Those contain caffeine, which induces water loss through the kidneys, so there is less for the rest of the body.  If anything, caffeinated beverages increase the water requirement.

How much water is enough?  Answer – Enough for YOUR body and circumstances.  No single amount, like 8 glasses per day, is accurate.  Our water goal varies according to body size, activity level, ambient temperature and to some extent, genetics.  We lose water through sweating and evaporation from the skin.  Water disappears in the body as it is broken down for use in metabolic processes.  We urinate sufficient water to flush out toxins, which depend on the rest of our diet. 

In general, we need at least one-third ounce per pound of ideal body weight (divide your healthy weight by three).  Add more if it’s hot outside, the heat in your house is super dry, you sweat a lot or you have diarrhea.  If you drink that amount and still have poor energy, dry skin, not much urine and/or hard stool, you need more.  Ideally the urine should not be dark, but don’t expect it to be colorless if you take a multi-vitamin (vitamin B2 turns urine yellow) or eat beets, which turns urine a pretty peach color. 

The one problem I have with asking people to drink more water is that they often translate that into number of 16.9 ounce bottles of water.  Those little plastic bottles are horrible for the environment and ocean animals.  Most of us live in communities that supply purified drinking water, therefore most of us have little excuse to obtain our water from plastic bottles.  

Everything has a potential downside. For water it is the danger of diluting our blood too much.  Too low a serum salt concentration can cause cramps, confusion, seizures and death.  This usually only happens in people who drastically limit salt intake while drinking more than a gallon (128 ounces) of water daily or take certain medications that affect water and salt balance.

In summary, we do our bodies a favor by staying well hydrated.  So, find a water temperature acceptable to you, add a non-caloric, non-mineral, non-medicinal, non-physiologically active (in other words, no boost) flavoring if necessary, and improve your physical existence.╣