Most people have probably heard the old rule that you should drink 8, 8-ounce glasses of water each day. Just as many other old rules, this one did not arise from scientific evidence. If you already knew that the 64-ounce rule was more of a rough guideline than a fact, you’re probably wondering how much water you really need.
If you check with different people and associations such as the Mayo Clinic, Institute of Medicine, and the American Dietetic Association, you’ll probably get some slightly different advice each time. The reason for these mixed messages is that there really is no perfect formula proven to decide exactly how much fluid a human needs each day. Most of these “mixed” messages all have the same meaning when you get down to it.
In general, if you follow the 64-ounce guideline, that is probably okay given that you are a healthy adult who does not engage in daily rigorous activities. However, you can basically trust your own instincts when it comes to fluid intake. Drink when you are thirsty. When you feel satisfied, you don’t need to keep drinking just to reach a daily ounce requirement. Another checkpoint is to check your urine aiming for a light yellow to clear color. Darker colors often signify dehydration. Remember that any fluid contributes to your body’s fluid requirements. Yes, this includes coffee and soda. Water is always the best, but it all counts. You also receive about 20% of your daily fluid from foods, on average.
Most people are certainly not in danger of this occurring; however, I want to warn everyone that it is indeed possible to die from too much water. This happens when you ingest much more water than electrolytes (sodium, potassium, and chloride) and your fluid to electrolyte ratio becomes imbalanced. This is extremely serious and mostly affects athletes who over hydrate without replacing electrolytes.
Here are some conditions that may increase your fluid needs:
Spending time outdoors in the heat
Increased fiber intake
Here are some conditions that may decrease your fluid needs:
Congestive heart failure
Kidney (renal) failure
For more personalized information about exactly how much water you should be ingesting, it is best to speak with your health care provider or a registered dietitian.
I avoid sugary drinks! The fact that one sugary drink daily could lead to about a 15 pound weight gain in a year, if I don't burn all of those calories off, is so not worth it!