Carbonated water may play a small role in weight management by slightly increasing blood sugar uptake and metabolism (the process your body uses to convert energy). However, the effect appears to be minimal. A brief analysis published in BMJ Nutrition Prevention and Health concluded that carbonated water alone is not sufficient to promote significant weight loss.
The author emphasizes that there is no easy solution to losing weight and keeping it off. Regular exercise and a balanced, healthy diet remain essential. Additionally, the long-term effects of consuming large amounts of carbonated water are still unknown.
Carbonated water is often seen as a helpful tool because it can make you feel fuller and may reduce hunger. It has also been suggested that it may help improve digestion and lower blood sugar levels, leading some to believe it may help with weight loss.
Unknown mechanisms behind the effects of blood sugar levels
Despite these claims, the exact mechanism by which carbonated water lowers blood sugar levels is not well understood. It is also unclear how such effects translate into meaningful weight management benefits.
To explore this further, the authors compared drinking carbonated water to hemodialysis. Hemodialysis is a medical process that filters (dialysis) the blood to remove waste products and excess body fluids when the kidneys are no longer able to perform their functions. This comparison is based on the results of previous studies.
What hemodialysis reveals about glucose use
During hemodialysis, the blood becomes alkaline, primarily due to the production of carbon dioxide (CO2). Similarly, the CO2 in carbonated water is absorbed through the lining of the stomach and quickly converted to bicarbonate (HCO3) within the red blood cells. This change in alkalinity can activate certain enzymes that increase the rate at which glucose is absorbed and used by the body.
Observations in clinical practice show that even if the starting blood glucose level in the dialysate is high, the blood glucose level decreases as the blood passes through the dialyzer.
Reasons why the impact on the real world is small
These findings suggest that carbonated water may slightly improve how the body uses glucose, but the overall effect is very limited. Context is important, the authors point out.
In a standard 4-hour hemodialysis session, approximately 48,000 ml of blood passes through the dialyzer. This process uses approximately 9.5 g of glucose.
“Given this minimal glucose reduction, the effect of CO2 in carbonated water is not an independent solution for weight loss. A balanced diet and regular physical activity are still important components of sustainable weight management,” he claims.
Possible gastrointestinal side effects
The authors also point out that carbonated water can affect your digestive system, especially if you have a sensitive stomach or already have gastrointestinal problems.
“Drinking carbonated water can also have some effects on the digestive system, especially for people with sensitive stomachs or pre-existing gastrointestinal conditions. Key concerns include bloating, gas, and in some cases worsening of certain symptoms associated with digestive disorders such as irritable bowel syndrome and gastroesophageal reflux disease,” he explains.
“Moderation is key to avoiding discomfort while still reaping the metabolic benefits that carbonated water can provide,” he says.
Experts urge caution
Professor Sumantra Ray, executive director of the journal’s co-owner, NNEdPro Global Food, Nutrition and Health Research Institute, stressed that the findings are still preliminary.
“There is a hypothesized link between carbonated water and glucose metabolism, but this has not yet been tested in well-designed human intervention studies.
“And while this study adds to the evidence base, it does not provide enough evidence to recommend preventive or therapeutic use of carbonated water. Additionally, the potential benefits must be weighed against the potential harms of carbonated drinks, which may contain sodium, glucose, or other additives.”
