Daily Fluid Intake For Adults

You need to drink fluids daily to avoid dehydration and maintain good health. Every system in your body needs water to work properly. Even mild dehydration can disrupt your body's ability to carry nutrients to cells, flush toxins from vital organs, maintain the proper temperature and perform other important functions. It also leaves you feeling fatigued. The amount of fluid you need each day depends on numerous factors, including what sex you are, your activity level and the temperature.

Dietary Guidelines for Americans

Your fluid intake includes water, the water in other beverages and the water in food. The 2010 Dietary Guidelines for Americans set the adequate intake, or AI, for water at 3.7 liters a day for men and 2.7 liters for women. That's about 16 cups of fluid daily for men and 12 cups for woman. However, that amount includes the fluid you get from foods like fruit and vegetables that contain water, which accounts for an estimated 19 percent of your total fluid intake. Thus, you need to drink 13 cups of fluid a day if you are a man and 9 cups if you are a woman, based on the AI set by the 2010 guidelines.

Physical Activity

The AI for fluid will work for you if you are not physically active, according to the dietary guidelines. You need more fluid if you exercise or are an athlete. Recommendations for athletes vary. According to Montana State University, your fluid needs are linked to your energy expenditure. MSU recommends taking in 1 ml to 1.5 ml of fluid for each calorie you burn throughout the day. That means if you expend 5,000 calories during the day, you need 5 to 7.5 liters, or 21 to 32 cups, of fluid daily to maintain fluid balance. According to the Peak Performance website, athletes on average need 1.5 liters, or 6.3 cups, of additional fluid, which translates to a total of 19.3 cups a day for men and 15.3 cups a day for women. However, factors such as the temperature where you are exercising, your sweat rate and your fitness level affect how much water you need.

Temperature

You also need more fluid if you are exposed to high or low temperatures instead of living in a temperate climate, according to the 2010 guidelines. Where it's hot, you need to replace fluids lost through sweating to help lower your body temperature. In a cold climate, you need more fluid to make up for loss of skin moisture due to indoor heat.

Considerations

You are likely getting enough fluid if you rarely feel thirsty and produce light yellow or colorless urine, notes MayoClinic.com. You should produce 1.5 liters, or 6.3 cups, of urine daily if you are adequately hydrated and urinate every two to three hours. If you are concerned about your weight, water and other non-calorie drinks are the best beverages for you because they don't add calories, according to the 2010 guidelines. It is possible to drink too much water, however. If you drink excessive water and do not replace electrolytes, you raise the risk for hyponatremia, a potentially fatal condition in which your plasma concentration of salt is too low. You have a higher risk for this condition if you are a woman or are elderly, according to the American College of Sports Medicine.