Ask the Dietitian: How Much Water Do I Really Need?

Stacy from Antigua sent me this great questions:

 I would like to know your recommendations for water intake.  I have seen that the recommended amount is half your body weight in ounces. How much water do I really need to drink each day?

Great question, Stacy, and very timely too. As the weather is getting hotter and hotter each day, we need to be very aware of our fluid needs and be careful to meet them. Half your body weight in ounces seems a high recommendation to me. However, we do need lots of water since the body is roughly 65% water. 

According to the American Dietetic Association’s Complete Food and Nutrition Guide, the average adult loses about two and a half quarts or about 10 cups of water daily. To maintain your body’s fluid balance, you need to replace it each day. 

So the 8-10 cups of water/day recommendation is pretty spot on. However, the truth is, you don't have to get the 8-10 cups that is needed per day just by drinking water. If you are eating a healthy diet, full of nutrient rich foods, such as fruits, vegetables, and low-fat dairy, you are also eating foods that are high in water. Yogurt, milk, grapefruit, lettuce, broccoli, and watermelon all have a water content of 85% or more! So all these foods can contribute to the 8-10 cups (64-80 ounces) needed per day. Also, remember all types of beverages count towards your water intake as well-even things like coffee or tea, but of course, nothing beats pure water when it comes to hydration!

And remember, if you are exercising or being active in the heat, you are losing fluids through sweat, and your fluid needs are even higher! In fact, water is the number one nutritional factor affecting athletic performance. You should aim to drink 14-22 ounces prior to exercising, 6-12 ounces of fluid during exercise, every 30 minutes, and after exercising drink at least 16 ounces for every pound of sweat lost during exercise (to figure this out, you need to weigh yourself immediately before and immediately after exercise, any pounds lost are water that needs to be replaced).

The best way to avoid dehydration is to stay hydrated by taking in plenty of fluids and high-water foods throughout the day. To do this, keep water at your desk, take a drink every time you walk by the water fountain, drink 1 glass of water for every cup of coffee you drink, eat more fruits and vegetables, and drink at least 8 ounces of water before each of your meals. If you follow these tips, you'll stay hydrated and beat the heat this summer!