Can Sparkling Water Spark Weight Loss?

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Carbonated water has been linked to satiety, gastric motility and lower blood glucose levels, though the mechanisms remain unclear. While this process could theoretically aid weight loss, the effect is likely minimal. Additionally, patients should be aware that consuming carbonated water may influence blood glucose readings.

“The consumption of carbonated water has become popular among health-conscious individuals, leading to discussions about its potential effects on weight loss,” wrote author Akira Takahashi, M.D., Ph.D., associated with the Dialysis Center at Tesseikai Neurosurgery Hospital in Japan. “While many advocate for its benefits, it is important to explore the underlying mechanisms more closely.”

In his brief report, published in BMJ Nutrition, Prevention & Health, he evaluated the physiological effects of carbonated water using data from a 2004 study referencing the mechanisms of hypoglycemia induced by hemodialysis.

Observations showed that carbon dioxide (CO₂) exposure in dialysis patients leads to lower blood glucose levels, similar to what might happen (to a lesser extent) when consuming carbonated water. Some studies suggest that carbonated beverages — particularly when they are high in sodium — might lower blood sugar levels, although Takahashi noted the reason why remains a mystery.

When you drink sparking water, CO₂ is absorbed into your bloodstream. Inside red blood cells, CO₂ is converted into bicarbonate, which makes the cells more alkaline. This change in pH activates enzymes that help break down sugar (glucose) faster by stimulating anaerobic glycolysis. As a result, more glucose is pulled from the bloodstream into cells, temporarily lowering blood sugar.

Regarding weight loss, the gas from carbonated water expands in the stomach, which can create a feeling of fullness and help reduce hunger. Weight loss can be amplified if a person swaps sugary beverages, such as soda and fruit juice, for sparkling water or diet drinks, further reducing caloric intake and added sugar.

Carbonated water may also indirectly promote weight loss by boosting anaerobic glycolysis and glucose utilization. However, Takahashi emphasized the importance of approaching these effects in context. Although carbonated water might slightly boost glucose metabolism, the effect is too small to lead to significant weight loss without keeping your diet in check.

“The CO₂ in carbonated water may support weight loss by converting to HCO₃- in red blood cells and increasing pHc to enhance glycolysis,” he stated. “However, because this glycolysis due to CO₂ consumes fewer calories, it should be integrated into a broader strategy of healthy living rather than relied on as a primary weight loss tool.”

Drinking sparkling water may lead to bloating, gas or digestive discomfort, especially if an individual has preexisting conditions such as gastroesophageal reflux disease (GERD) or irritable bowel syndrome (IBS). Takahashi also points to evidence that CO₂ levels in the breath are connected to blood sugar levels. Therefore, drinking seltzer before testing your blood sugar can temporarily impact readings.

However, the benefits of drinking sparkling water include increased hydration, which can decrease the likelihood of headaches, constipation and kidney stones. Additionally, as the body can confuse dehydration for hunger, drinking more low-calorie beverages can lead to consuming fewer calories, thus encouraging weight loss.

Takahashi supports further research aimed at better understanding the long-term effects of drinking sparkling water and optimizing its role in dietary interventions.