Yes, sparkling water hydrates you just as effectively as still water. The carbonation in sparkling water does not reduce your body’s ability to absorb the fluid, and research confirms that carbonated and non-carbonated water perform equally when it comes to maintaining hydration. So if you prefer the fizz, you’re not sacrificing anything on the hydration front.
Why Carbonation Doesn’t Change Hydration
Sparkling water is simply water infused with carbon dioxide gas under pressure. Once you drink it, the bubbles don’t interfere with how your body processes the liquid. A study on gastric emptying, the rate at which fluid moves from your stomach into your small intestine for absorption, found that carbonation has no effect on this process. Your body absorbs carbonated water at the same speed as flat water.
This matters because gastric emptying rate is one of the key factors that determines how quickly a beverage actually hydrates you. Interestingly, the same study found that flavoring additives (like those in low-calorie sports drinks) slowed stomach emptying by as much as 25%, but the carbonation itself made no difference.
What the Beverage Hydration Index Shows
Researchers developed a tool called the Beverage Hydration Index to measure how well different drinks keep you hydrated over time, based on how much fluid your body retains versus how much it excretes as urine. In this randomized trial, sparkling water scored the same as still water. Beverages like milk actually ranked higher than both, largely because milk contains protein, fat, and electrolytes that slow fluid loss. But among waters, carbonation is a non-factor.
One Reason to Skip It During Exercise
While sparkling water hydrates you fine in everyday life, it’s not ideal during a workout. The carbonation can cause bloating and a feeling of fullness that makes it harder to drink enough fluid when you’re sweating heavily. This isn’t a hydration chemistry problem. It’s a comfort problem. You’re less likely to keep sipping if your stomach feels stretched with gas. For exercise, flat water or a sports drink is more practical.
Bloating and Digestive Sensitivity
The carbon dioxide in sparkling water produces gas in your digestive tract, which can cause belching, bloating, or discomfort in some people. Johns Hopkins Medicine specifically recommends that people with irritable bowel syndrome avoid carbonated beverages, noting that the fizzy effect in the GI tract can aggravate symptoms. If you have IBS or are prone to bloating, sparkling water might not be worth the trade-off even though it hydrates well.
For most people without digestive conditions, the bloating from sparkling water is mild and temporary. It tends to be more noticeable if you drink large amounts quickly.
Effects on Teeth and Bones
Dissolving carbon dioxide in water creates a weak acid called carbonic acid, which lowers the pH slightly. Plain bottled water has a neutral pH of 7, while a carbonated water like Perrier comes in around 5.25. The American Dental Association considers this “minimally corrosive.” It’s far less acidic than orange juice, coffee, or soda, and the erosion risk to tooth enamel is very low for plain sparkling water. Flavored varieties with added citric acid are more acidic and worth being more cautious about.
As for bone health, a large study from the Framingham Osteoporosis Study found no link between noncola carbonated beverages and lower bone mineral density. Cola specifically was associated with reduced bone density in older women, likely due to its phosphoric acid content. Plain sparkling water contains no phosphoric acid, so the “carbonation weakens bones” concern doesn’t apply here.
Watch the Sodium on Certain Brands
Not all sparkling water is created equal. Plain seltzer typically contains nothing but water and CO2. Club soda, on the other hand, has added minerals, and a 12-ounce can contains roughly 75 milligrams of sodium. Some sparkling water brands go much higher. The American Heart Association has flagged that certain brands contain up to 1,000 milligrams of sodium per serving, nearly half the recommended daily limit of 2,300 milligrams. If you’re drinking several cans a day, that sodium adds up fast.
Check the label. If the ingredients list only carbonated water, you’re fine. If you see sodium bicarbonate, sodium citrate, or other sodium compounds, factor that into your daily intake, especially if you’re managing blood pressure.
Can Carbonation Make You Hungrier?
One surprising finding: carbonation may stimulate appetite. A study published in the journal Obesity Research and Clinical Practice found that carbonated beverages increased levels of ghrelin, the hormone that signals hunger, in both rats and a group of 20 healthy human men. The rats consuming carbonated drinks over a year-long period gained weight faster than those drinking flat versions of the same beverages, and they ate more food overall.
This doesn’t mean sparkling water will make you gain weight. The effect was studied alongside sugary carbonated drinks, and the practical impact of plain sparkling water on appetite in everyday life isn’t well established. But if you’re closely managing your calorie intake, it’s worth being aware that the fizz itself might nudge your hunger signals up slightly.
How Much Sparkling Water Is Fine
There’s no official cap on sparkling water intake, but nutrition experts recommend not making it your only source of fluids. As one dietitian told the American Heart Association, sparkling water “can contribute beautifully” to your total daily fluid intake, but variety matters. Some flat water throughout the day is a reasonable approach, with sparkling water filling in wherever you enjoy it. The main practical limits come down to sodium content (check the label), digestive comfort (back off if you’re bloated), and dental exposure (don’t sip flavored varieties with citric acid all day long).