Sparkling water is significantly better for you than soda by almost every measure. A standard 12-ounce can of soda contains 7 to 10 teaspoons of added sugar and around 150 calories. Plain sparkling water has zero sugar, zero calories, and hydrates you just as well as still water. The gap between the two drinks is wide enough that swapping soda for sparkling water is one of the simplest health upgrades you can make.
That said, not all sparkling waters are created equal, and carbonation does come with a few minor trade-offs worth understanding.
Sugar and Calories: The Biggest Difference
The most important reason sparkling water wins is what soda puts into your body. Harvard’s School of Public Health notes that the average can of sugar-sweetened soda or fruit punch delivers about 150 calories, nearly all from added sugar. Over the course of a day, two or three cans adds up to a meal’s worth of calories with no nutritional value. That sugar load is linked to weight gain, type 2 diabetes, heart disease, and tooth decay.
Plain sparkling water sidesteps all of this. It’s just water with dissolved carbon dioxide. No sugar, no calories, no sweeteners. If you’re drinking two sodas a day and switch to sparkling water, you’d cut roughly 2,100 calories per week without changing anything else about your diet.
Hydration Is Identical
One common concern is whether the carbonation in sparkling water makes it less hydrating. It doesn’t. Research using the Beverage Hydration Index, which measures how much fluid your body actually retains after drinking, found that sparkling water performed identically to still water. The bubbles don’t interfere with absorption. If you prefer the fizz and it helps you drink more water throughout the day, that’s a net positive.
The Acid Question: Teeth and Bones
Soda is hard on your teeth because of phosphoric acid and citric acid, both of which are strong enough to dissolve tooth enamel over time. These acids are what give cola its tangy bite and keep its pH well below the threshold (around 4.0) where enamel starts to erode. Carbonic acid, the weak acid formed when CO₂ dissolves in water, is far less damaging. Plain sparkling water sits at a higher pH and lacks the aggressive acids that make soda erosive.
There’s an important caveat here. Some flavored sparkling waters contain added citric acid to boost their fruity taste. Those products can dip below that pH 4.0 danger zone, making them more erosive than plain seltzer. If you’re drinking flavored varieties regularly, check the ingredients for citric acid. Plain seltzer or mineral water without added acids poses minimal risk to your enamel.
Bone health is another area where soda has a worse track record. Studies have linked cola consumption to lower bone mineral density, likely because of its phosphoric acid content. Carbonation itself doesn’t seem to be the problem. A clinical trial published in the British Journal of Nutrition compared postmenopausal women drinking a quart of carbonated mineral water daily with women drinking the same amount of still mineral water. After eight weeks, there was no difference in markers of bone turnover between the two groups. Non-cola carbonated drinks in general showed no association with lower bone density.
Digestive Effects of Carbonation
The carbon dioxide in sparkling water can cause bloating, gas, and mild discomfort in some people, particularly those with irritable bowel syndrome. The gas expands in your stomach, which is why you might feel fuller after drinking sparkling water than you would after still water. For most people, this is harmless and temporary.
You may have seen headlines claiming that carbonated drinks increase ghrelin, the hormone that triggers hunger, potentially leading to weight gain. That finding came from a small 2017 study, but the key detail is that the research was conducted primarily in rats drinking sugary carbonated beverages, not plain sparkling water. There’s no clear evidence that carbonation alone drives hunger or weight gain in humans.
How Sparkling Water Compares to Diet Soda
Diet soda eliminates the sugar problem, which makes it a closer comparison. Both diet soda and sparkling water are calorie-free and won’t spike your blood sugar. But diet soda still contains phosphoric acid (in colas) or citric acid, making it harder on your teeth and potentially on your bones. It also contains artificial sweeteners or sugar alcohols, which can cause bloating, gas, and diarrhea in some people. Researchers are still investigating how long-term use of these sweeteners affects gut bacteria, hunger signaling, and sugar cravings.
Sparkling water avoids all of those unknowns. If you’re choosing between the two, plain sparkling water is the cleaner option.
Watch for Hidden Ingredients
Not every bottle labeled “sparkling water” is the same. Here’s what to look for:
- Club soda contains added sodium to mimic mineral water. The amount per serving is small, but it adds up if you’re drinking several cans a day. Most Americans already consume more sodium than recommended, so this is worth tracking if you have blood pressure concerns.
- Flavored seltzers may contain citric acid, which increases acidity enough to erode enamel with frequent exposure. Check the ingredients list rather than assuming “natural flavors” means nothing was added.
- Plain seltzer and mineral water are the simplest options. Seltzer is just carbonated water. Mineral water contains naturally occurring minerals from its source, which can include small amounts of calcium and magnesium.
If you’re using sparkling water as a full-time soda replacement, sticking with plain or naturally flavored varieties without citric acid gives you the benefits of carbonation without the downsides of added acids or sodium.