By Sandee LaMotte, CNN

(CNN) — Fizzy, sparkling, carbonated or seltzer — no matter what you call it, water that tickles your nose is fun and refreshing, and for some, a welcome change from its flat cousin.

On social media, sparkling water has gained a following for its impact on body mass. Some believe fizzy water may increase weight, pointing to a February 2017 study that found carbonated beverages stimulate appetite by increasing ghrelin, the hunger hormone. However, that research was done in male rats and only 20 people and has never been replicated.

The more popular theory is that carbonated water may lead to weight loss. Fizzy bubbles may boost a feeling of fullness, and water itself helps the body burn fat by boosting metabolism — in fact, water is a critical part of lipolysis, which is how the body turns stored fat into energy.

A new study explores a third explanation: Carbonated water may also lower blood glucose levels. That’s beneficial for weight loss, experts say, because if blood sugar is kept on an even keel, with few spikes or dips, the body’s cells can more effectively burn fat between meals for energy.

“When carbonated water is consumed, CO2 is absorbed into the blood vessels in the stomach,” said study author Dr. Akira Takahashi, a physician in the dialysis center at Tesseikai Neurosurgical Hospital in Shijonawate, Japan, in an email.

While some carbonated water is natural, created as volcanic gases infuse the water in natural springs with bubbles and minerals, most sparkling water is made by forcing carbon dioxide, or CO2, into water under intense pressure.

Once in the blood, CO2 is rapidly converted into bicarbonate ions as part of a process that maintains pH balance. This conversion then causes red blood cells to become more alkaline, Takahashi said. This increased alkalinity accelerates the process of glucose consumption in red blood cells, thus lowering glucose levels.

No significant weight loss

The study, published Tuesday in the journal BMJ Nutrition, Prevention & Health, was built upon 2004 research by Takahashi and his team on hemodialysis, a process that occurs during kidney dialysis when blood is filtered to remove waste and excess water. During hemodialysis, CO2 enters the blood, just as it does when carbonated water is consumed.

While the November 2004 study did show blood sugar levels decrease when CO2 is added to blood, the new study concluded the amount of glucose burned during this process would not be enough for any significant weight loss.

“Red blood cells cannot fully ‘burn’ the glucose, and it will be recycled by the liver,” said Keith Frayn, a professor emeritus of human metabolism at the University of Oxford in the UK, who was not involved in the study.

“If fizzy drinks were to be shown to lead to weight loss, it would much more likely be through effects on feelings of fullness,” Frayn said in a statement. “In the meantime, however, sugar-sweetened fizzy drinks are recognized as a source of excess calories and likely to do just the opposite.”

In addition, blood sugar levels were only temporarily lowered, Takahashi said, and the carbonated water would have a slight effect on calorie consumption.

“Therefore, carbonated water alone is unlikely to contribute significantly to weight loss,” he said. “A balanced diet and regular exercise remain essential for effective weight management.”

Use for optimal health

Studies have shown people who drank two cups of water before meals lost more weight than those who did not. Another study found people who replaced diet beverages with water also benefited by losing pounds.

“Some of the patients I see for weight loss never feel satisfied,” said Welstead, who was not involved in the new study. “These are the folks who tell me, ‘I’m always hungry and I’m always waiting for a snack,’ and I think it can really help some of those people.”

Still, filling your belly with bubbly water can increase satiety and may be especially helpful for people who struggle with hunger pains, said registered dietitian Lori Welstead, who specializes in gastrointestinal nutrition at University of Chicago Medicine, a not-for-profit academic medical health system.

“But be mindful of excess or added sugars, including some of the fake sugars, because those may be negative metabolically,” she said.

Other patients say they benefit from fizzy waters because the bubbles help clear their esophagus and stomach and move food along in the digestive system, she said.

“Some people with a ‘slow’ stomach, so to speak, find carbonation helps with their gut motility,” Welstead said. “So we have some people for whom these sparkling or tonic waters can create fullness, and others for whom it helps with digestion.”

But don’t overdo it, she warns — more than one or two sparkling waters a day could really exacerbate gas and abdominal pain from the carbonation.

“If someone’s coming in and they’re saying, ‘Oh my gosh, I’m gassy, I’m bloated, I’m burping, I’m feeling so sick all day,’ it could be due to drinking five cans of carbonated water each day.”

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