Does Soda Dehydrate You?

What’s in Soda?

Soda gets a bad rap for many reasons. The typical can of soda contains around 150 calories, 9-13 teaspoons of sugar (usually from high fructose corn syrup), up to 70 mg of caffeine, and about 55 mg of sodium. While the sugar and calories can easily wreck a diet, a can every now and then isn’t the end of the world. The average American, however, drinks 1.6 cans of soda a day, totaling nearly 600 cans of soda a year.

Caffeine, the most widely used drug in America, is a stimulant with a mild diuretic effect. It releases adrenaline in the body, which puts the body in a state of “fight or flight.” In addition to the side effects like increased heart rate and blood pressure, it also slightly increases urine output. Caffeine is also addictive, causing many people to feel they have to drink a caffeinated beverage in order to function at their usual level.

Sugar and salt in large amounts can cause slight dehydration. In smaller amounts, though, they may just make the person eating or drinking the salt and/or sugar feel thirsty.

Soda and Dehydration

While many experts agree that eight glasses of water a day is more than needed, no one seems to have come up with just how much liquid we need to drink to replenish our bodies. What they do tend to agree on, though, is that the liquid to keep the body hydrated can come from a variety of sources, such as food, water, juice, milk and yes, even soda.

However, what about the caffeine, salt and sugar? Experts seem to be on both sides of the argument. All signs point to the fact that soda should dehydrate you due to the combination of caffeine, sodium and sugar. Having one can of soda, though, won’t actually cause dehydration. The relatively small amount of caffeine in just one can will cause about the same urine output as a glass of water. The sodium and sugar in the soda may make you feel slightly thirstier, but just one can shouldn’t cause noticeable dehydration.

Moderation to Avoid Dehydration

Experts may never agree on whether or not soda causes dehydration, but the easiest way to protect your body is to drink soda only in moderation. One can of soda every now and then shouldn’t have a serious impact on your body or your health. Drinking multiple cans of soda a day, however, adds hundreds of calories to your diet and puts a lot of caffeine in your body. Soda, both regular and diet soda, is also nutritionally deficient, meaning there are no vitamins, minerals, or other nutrients your body needs. Drinking three or four servings of soda a day ultimately takes the place of other, more nutritionally valid drinks, such as milk or juice. Sticking to just one can of soda once in a while means you won’t have to ask, “Does soda dehydrate you?”

References:

Palmer, Janice. “Armstrong’s Study Shows Caffeine Does Not Increase Dehydration.” https://advance.uconn.edu/2002/020722/02072207.htm.

Zinczenko, David and Matt Goulding. Eat This, Not That. Rodale, 2009.