As a result of the unrelenting heat outside (Who else is ready for fall?!), I’ve had a lot of questions pop in my mind about hydration lately. To answer these questions for myself, I looked to experts in nutrition. However, there’s a lot of conflicting advice out there. I did my best to sort through the opinions and find the truth about proper hydration. Here’s what I found:
What drinks, other than water, count toward my daily water intake?
Although water is a calorie-free, inexpensive option, sometimes I want to switch it up. Luckily, there are many alternatives to water that can increase your water intake. First, milk is very hydrating (some studies even say it’s more hydrating than water) and contains important nutrients (e.g., calcium, vitamin D) as an added bonus. Regarding coffee and tea, a common myth states that caffeinated beverages are dehydrating due to their diuretic effect. However, this myth has been debunked by scientists; coffee and tea do, in fact, count toward your daily hydration goals. Finally, juice and soda also contribute to water intake, although they should be limited due to their high sugar content.
Is it possible to drink too much water?
It is – but it’s uncommon. Overhydration, or water intoxication, typically involves drinking more than 1.5 liters (or about 6 glasses) of water in an hour.1 Your kidneys cannot process this much water, resulting in an imbalance of liquid and electrolytes in your cells. When exercising for long periods of time or in extreme heat, consider alternating between water and sports drinks such as Gatorade to maintain a healthy electrolyte balance. Otherwise, just stick to water.
What’s with the 8×8 recommendation?
According to the 8×8 recommendation, adults should drink eight, eight-ounce glasses of water each day. The problem with this common recommendation is that it assumes everyone’s needs are equal. On the contrary, individuals have differing water needs depending on their activity level, environment, and health status.2 According to the Mayo Clinic, eight eight-ounce glasses of water per day may be more than enough for some, while not enough for others.2 To gauge your own ideal water intake, use a journal to document your daily water intake, along with your thirst level and urine color. You are properly hydrated if you rarely feel thirsty and have colorless/light yellow urine.2
Other than decreased physical performance, how does dehydration impact the body?
When your body doesn’t have enough water, it does not function properly. This extends far beyond just physical performance, such as in sports and exercise. For example, dehydrated individuals may have trouble with concentration and memory.3 Additionally, dehydration can increase tiredness, confusion, and irritability.3 Hydration may also aid in gastrointestinal, kidney, and heart function.3
How much water do you get from food?
In the U.S., studies have shown that people typically consume around 20% of their daily water intake from food.3 However, this percentage varies widely between individuals depending on their diet. If you’re looking to gain more hydration from your diet, consider eating more fruits, vegetables, soups, dairy products (e.g., yogurt, cottage cheese), fish/shellfish, pasta, beans, and/or chicken.3
1Morris R. Hydration and Hyponatremia: Can You Drink Too Much Water? Water Quality and Health Council. https://waterandhealth.org/safe-drinking-water/drinking-water/hydration-and-hyponatremia-can-you-drink-too-much-water/. Published July 26, 2019. Accessed September 7, 2020.
2Mayo Clinic. Water: How much should you drink every day? https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/water/art-20044256. Published September 6, 2017. Accessed September 7, 2020.
3Popkin BM, Danci KE, Rosenberg IH. Water, hydration, and health. Nutrition Reviews. 2010;68(8):439-458. doi:10.1111/j.1753-4887.2010.00304.x.