However, the effects of sparkling water on metabolism are small, and drinking fizzy water on its own without making any other diet or exercise changes isn’t likely to help anyone lose weight, the research concluded.
Sparkling Water Slightly Changes Blood pH Levels
Akira Takahashi, MD, a researcher and physician at Tesseikai Neurosurgical Hospital in Shijonawate, Japan, designed the study to investigate what happens in the body when people drink sparkling water.
Carbonated water, also known as seltzer or fizzy water, is water that has been infused with carbon dioxide gas (CO2) under pressure. This process creates bubbles and gives the water its signature effervescence.
Although many people report feeling fuller after drinking seltzer, scientists aren’t clear on how the drink may impact blood sugar levels or how this might contribute to weight loss.
To find out more, Dr. Takahashi compared the process of drinking sparkling water with dialysis, a process in which a machine filters blood to remove waste and excess water when the kidneys no longer can adequately perform this function.
His data showed that when carbon dioxide enters the blood and red blood cells, it changes the pH. The slight increase in alkaline in the blood allows the cells to absorb a little more glucose, which lowers blood sugar levels.
“Given this minimal glucose reduction, the impact of CO2 in carbonated water is not a standalone solution for weight loss,” said Takahashi.
Even so, “I’ll be interested to see where this research goes,” says Kate Donelan, RD, registered dietitian at Stanford Healthcare in California, who was not involved in the study. ”People with diabetes might be interested in this research as it can impact their efforts to manage blood sugar,” she suggests.
Sparkling Water May Help You Feel Full
Beyond the impact on metabolism and blood pH levels, there are reasons why people looking to lose weight may turn to sparkling water.
“General weight loss advice recommends increasing intake of fluid, fiber, and protein as a means of amplifying satiety with lower calorie intake,” says Donelan.
“There’s some research to suggest that the carbonation found in sparkling water increases satiety more than other fluids by increasing stomach distension,” Donelan says.
Usually people don’t like bloating, but that feeling of fullness can lead them to eat smaller portions or avoid unnecessary snacking, says Donelan.
“Anecdotally, most people do report increased stomach distention after drinking carbonated drinks, so I think the concept that it can increase satiety without increasing calories is valid,” says Donelan.
Sparkling Water May Affect a Hunger Hormone
Not all research supports the idea of carbonated water as helpful for weight loss. Some studies suggest drinking sparkling water raises levels of the hormone ghrelin in the body, which can increase hunger — “although the significance of this is unclear,” Donelan says.
Is Sparkling Water a Healthy Choice for Weight Loss? Depends on What You’re Replacing
“In nutrition, we can never look at a food alone and judge it ‘good’ or ‘bad.’ We have to consider what you would eat instead,” says Donelan.
“Drinking sparkling water is a very realistic way to contribute to weight loss goals, especially if these drinks are replacing sugar-sweetened beverages such as soda, juice, and sports drinks,” says Donelan.
Drinking Any Kind of Water With Food Could Help You Eat Less
“Drinking fluids with meals for help with portion control could be one small and achievable goal that a person sets on their journey to a healthier weight,” says Rebecca Beaudoin, RDN, a nutrition therapist with Nebraska Medicine in Omaha, Nebraska, who was not involved in the study.
Sparkling water might not be an appealing option for people who don’t want to feel bloated, she says — in which case, opt for tap water.
For people who enjoy sparkling water, Beaudoin recommends including it along with other strategies that help with weight loss or management, such as reducing overall calories, increasing physical activity, and adding more fruits, vegetables, fiber, and nutrient-dense foods to your daily diet.
“I often remind patients that it is the overall pattern of their diet and lifestyle, not one specific thing, that makes the most impact on our health,” says Beaudoin.