Bubbles for weight loss? Study finds carbonated water may incrementally boost metabolism

Fizzy water might aid weight loss by boosting blood glucose uptake and metabolism, according to an analysis published in the open access journal, BMJ Nutrition Prevention & Health. However, the findings show that these effects are so small, drinking it can’t be relied upon alone to help people shed the pounds. 

There are no quick fixes to slimming down and keeping off weight, highlights Dr. Akira Takahashi, a physician in the dialysis center at Tesseikai Neurosurgical Hospital in Shijonawate, Japan, who authored the study.

Because fizzy water is “filling,” thereby helping to curb hunger pangs, and reportedly speeds up digestion and lowers blood glucose levels, it has been heralded as a potential slimming aid.

But it’s not clear exactly how carbonated water might reduce blood glucose or how this might contribute to weight management, points out the author.

“Given this minimal glucose reduction, the impact of CO₂ in carbonated water is not a standalone solution for weight loss. A balanced diet and regular physical activity remain crucial components of sustainable weight management,” he insists.

Comparisons with hemodialysis

In his investigation, Dr. Takahashi compared the process of drinking fizzy water with hemodialysis, whereby blood is filtered (dialyzed) to remove waste and excess water when the kidneys no longer can, drawing on previously published research.

Hemodialysis turns blood alkaline, primarily producing carbon dioxide (CO₂). Similarly, the CO₂ of fizzy water is absorbed through the stomach lining and is rapidly converted to bicarbonate (HCO3) in red blood cells.

This alkalinization process speeds up glucose absorption and use by activating key enzymes in red blood cells, explains Dr. Takahashi.

The study alone does not offer sufficient evidence on which to make recommendations for the preventive or therapeutic use of carbonated water.Clinical observations during hemodialysis show that blood glucose levels fall as blood passes through the dialyser, despite a higher glucose level in the dialysate solution to start with, he adds.

“While there is a hypothetical link between carbonated water and glucose metabolism, this has yet to be tested in well-designed human intervention studies,” notes professor Sumantra Ray, executive director, NNEdPro Global Institute for Food, Nutrition and Health, which co-owns the journal.

“And although this study adds to the evidence base, it doesn’t provide sufficient evidence on which to make recommendations for the preventive or therapeutic use of carbonated water. Additionally, any potential benefits must be weighed up against the potential harms of carbonated drinks, which may contain sodium, glucose or other additives.”

Context is key

While these findings suggest that fizzy water may indirectly promote weight loss by enhancing the uptake and use of blood glucose, context is key, stresses Dr. Takahashi.

During a typical four-hour hemodialysis session, around 48,000 ml of blood flows through the dialyzer, resulting in around 9.5 g of glucose being used during the session, he explains.

“Also, drinking carbonated water can have some effects on the digestive system, particularly for individuals with sensitive stomachs or pre-existing gastrointestinal conditions,” he notes.

“The primary concerns include bloating, gas and, in some cases, exacerbation of certain symptoms associated with digestive disorders, such as irritable bowel syndrome or gastroesophageal reflux disease.”

“Moderation is key to avoiding discomfort while still enjoying the possible metabolic benefits of carbonated water.”

In other weight management news, Nexira unveiled a natural botanicals-based GLP-1 supplement range for sustainable weight management. The company’s latest innovation highlight is Carolean, a patent-pending ingredient specifically developed to promote natural GLP-1 secretion and support appetite control.

Earlier this month, Personalized Health Rx launched its direct-to-consumer telehealth weight management platform, integrating weight-loss medications, customized nutritional support and board-certified doctor guidance.

Weight management app Noom also revealed a major update to its GLP-1 Companion service to accompany and optimize popular GLP-1 drug therapies, which can cause temporary and long-term side effects like critical nutritional gaps and muscle loss.