How much water should I drink every day? It sounds like a pretty simple question; however, the answer may not be as straightforward as fitness magazines and people might suggest.
Why is adequate hydration important, especially in these hot summer months? According to the Centers for Disease Control and Prevention (CDC), drinking water can prevent dehydration, a condition that can cause unclear thinking, dizziness, restlessness, muscle cramps and even constipation and kidney stones.
Everyone has heard the rule of thumb to drink eight glasses of water a day. But are those 8-ounce glasses, 16 ounce, 20 ounce? The rule of thumb would be better stated as 8 cups of water a day, so eight 8-ounce servings a day to total 64 ounces. But again this is just a simple estimate.
Other sources recommend dividing your body weight in half and drink that number of ounces of water every 24 hours. But this may significantly overestimate fluid needs, especially for those who are overweight, and it does not account for other beverages and water obtained from food.
The Institute of Medicine of the National Academies has set general recommendations for water intake. Women who appear to be adequately hydrated should consume an average of approximately 2.7 liters (91 ounces) of total water each day, and men an average approximately 3.7 liters (125 ounces) daily from all beverages and foods. These guidelines have been mistakenly quoted be some as a recommendation for only water consumption, which also overestimates the amount of water people should drink each day.
Fluid intake should include all beverages consumed (with water being the preferred beverage), including tea, coffee, milk and soda (although that should not be a frequently consumed beverage). It also includes water contained in foods such as fruits, vegetables, soups and others, which can contribute 20 to 25 percent of daily fluid/water intake.
These amounts should be adequate for most people. Those who are very physically active, work outdoors or who live in hot climates may need to consume more water. Water is the preferred beverage for hydration, and when exercising you should drink before, during and after exercise. A general recommendation for athletes or those doing physical activity in hot weather for over an hour is to rehydrate with either fruit juice diluted with water or a sports drink, which will provide carbohydrates for energy plus minerals to replace electrolytes lost in your sweat.
Many factors affect our fluid needs, but fluid intake driven by thirst and the routine consumption of beverages at meals is sufficient for the average person to maintain adequate hydration.
Registered dietitian Barb Walsh is the community nutrition educator in the Tevis Center for Wellness.