Sparkling water fans might be interested to know the carbonated drink may “promote weight loss”, according to a recent paper published in the BMJ Nutrition Prevention and Health.
The study suggested the fizzy drink might enhance glucose uptake, thus “speeding up” our metabolism, which is the rate at which the body uses and converts energy.
But is it that straightforward? Here’s what you need to know...
Why does the paper say sparkling water boosts your metabolism?
The authors of the paper said that part of the reason the drink has been linked to potential weight loss is because it keeps you feeling full.
But they also claim it might create a slight uptick in how much blood glucose our cells use (or how “fast” our metabolism is). The more energy your body uses at rest, the more calories you burn, which can lead to weight loss.
Researchers aren’t sure why sparkling water might cause that change, but this paper compared the process of drinking fizzy water with haemodialysis, where blood is filtered to remove waste and excess water.
Haemodialysis turns blood alkaline, primarily producing carbon dioxide (CO2).
Similarly, when you drink fizzy water, CO2 is absorbed into the blood vessels in the stomach.
Study author Dr Akira Takahashi, a physician in the dialysis centre at Tesseikai Neurosurgical Hospital in Shijonawate in Japan, told CNN that once CO2 is in the blood, it’s turned into bicarbonate ions as part of a process that maintains pH balance.
The doctor said this then causes red blood cells to become more alkaline, which speeds up the process of glucose consumption in red blood cells – and then lowers glucose levels.
The BMJ paper speculated that drinking fizzy water might have similar results, which might in turn promote weight loss.
But the effect wasn’t proven in the study and is likely to be tiny if present– indeed, the authors of the paper stressed that the changes would be far too small to actually cause weight loss by drinking sparkling water alone.
So will drinking sparkling water make me lose weight?
The potential metabolic changes are interesting, but according to Catherine Collins, an NHS intensive care unit dietitian, “the short answer from this UK dietitian is a robust ‘NO’”.
Speaking to the Science Media Centre, she said that the haemodialysis link is “purely speculative” (which the researchers themselves admit), adding that any pH changes are likely to be tiny if present.
Dr Keith Frayn, Professor of Human Metabolism at the University of Oxford, also told the publication: “Even if it were possible to show that the carbon dioxide in fizzy drinks increases the use of glucose by red blood cells, that will not necessarily lead to weight loss, however minimal.”
He added: “Red blood cells cannot fully ‘burn’ the glucose, and it will be recycled by the liver,” stating that any weight loss benefits are likely to come from potential, but contested, appetite suppression.
If you’re seeking to lose some pounds, it seems diet and exercise – rather than bubbly bevvies – are the way forward.