As January progresses, many people may still be focused on their New Year’s resolutions, with some aiming to shed a few extra pounds gained over the holiday season.
So, if you’re among those looking to lose weight, could a crisp, refreshing glass of sparkling water be the secret to reaching your goals?
A study published Tuesday in BMJ Nutrition, Prevention & Health, suggests the CO2 in carbonated water might help with weight loss by boosting how red blood cells take in and process glucose.
“The consumption of carbonated water has become popular among health conscious individuals, leading to discussions about its potential effects on weight loss,” said the study’s author, Dr. Akira Takahashi, a physician in the dialysis centre at Tesseikai Neurosurgical Hospital in Shijonawate, Japan.
“While many advocate for its benefits, it is important to explore the underlying mechanisms more closely,” he said in the study.
Carbonated water, also known as sparkling water or seltzer, is simply water infused with carbon dioxide bubbles.
Many social media users swear by sparkling water for weight loss, claiming it aids digestion, helps you feel fuller for longer and is a healthy choice (as long as it contains no sugar).
On the other hand, some warn that fizzy water might contribute to weight gain, pointing to a 2017 study published in Obesity Research and Clinical Practice that found carbonated drinks increase appetite by raising ghrelin, the hunger hormone.
But that study was based on research conducted on 20 male rats. The findings suggested that rats consuming fizzy beverages throughout about a year gained weight more quickly than those drinking regular degassed carbonated beverages or tap water.
Hélène Charlebois, a registered dietician based in Ottawa, said drinking a glass of water, carbonated or not, before a meal is always a great trick to make yourself feel more full.
“Whether carbon is going to be better than water, I don’t know, there is not a lot of good concrete research to say it does,” she told Global News.
“I don’t want people just to drink carbonated thinking it will help them lose weight. But I would say an individual, if it makes you eat less and you feel fuller longer, it may work for you.”
Previous research suggests that carbonated water may contribute to weight management in a few ways, the study argues.
First, the bubbles in carbonated water expand within the stomach, creating a feeling of fullness or satiety, which can help individuals feel satisfied with smaller meal portions.
Second, some studies show that carbonated water, especially with added sodium, may contribute to lower blood sugar levels. However, Takahashi said the precise mechanisms behind this effect are still under investigation by researchers.
In his study, Takahashi said he aimed to explore the physiological effects of carbonated water in more detail, particularly its impact on glucose metabolism, building on his own 2004 research and investigating how these effects might contribute to weight management.
The latest study was not put through any clinical trials.
The study found when a person drinks carbonated water, the bubbles (which are mostly carbon dioxide) get absorbed into the blood. Inside the red blood cells, this carbon dioxide triggers a chemical reaction, making the cells slightly more alkaline, which boosts how quickly they burn sugar.
The study compares this to what happens during dialysis, where blood is filtered outside the body. During dialysis, carbon dioxide also enters the blood, and it’s observed that blood sugar levels actually decrease, even though the dialysis fluid itself contains some sugar.
Should you grab that fizzy water?
Takahashi warned that while this sugar-burning effect may happen, it is a very small change.
“The amount is so small that it is difficult to expect weight loss effects solely from the CO2 in carbonated water,” he said, adding that fizzy water alone won’t make someone lose weight.
“A balanced diet and regular physical activity remain crucial components of sustainable weight management,” he added.
Charlebois explained that while carbonated drinks might make you feel temporarily full, they are still liquids, and your brain will likely recognize that they don’t contain many calories. So, it might be a good idea to enjoy carbonated water alongside something healthy, such as an apple.
“But for weight loss, it’s more complicated. If it can help you reduce some calories, great. But as far as keeping your diet stable and just introducing that thinking you’re going to lose weight, it’s not going to work,” she said.
“Unless you’re combining it with food, it’s going to go through the stomach pretty fast and into the intestinal tract, and once it’s there, your stomach is still going to be wanting food.”
She noted that some of her clients consume an entire case of fizzy water a day in their desperation to lose weight. However, she cautioned against overindulging, as excessive carbonated water can lead to side effects like an irritated esophagus.
This concern was echoed in the study’s findings.
“Drinking carbonated water can have some effects on the digestive system, particularly for individuals with sensitive stomachs or pre-existing gastrointestinal conditions. The primary concerns include bloating, gas and, in some cases, exacerbation of certain symptoms associated with digestive disorders, such as irritable bowel syndrome, or gastro-oesophageal reflux disease,” the study said.
“Moderation is key to avoiding discomfort while still enjoying the possible metabolic benefits of carbonated water,” it added.
