Fizzy water linked to 'hunger hormone' - and weight gain
Think twice the next time a restaurant waiter comes out with the standard question "still or sparkling?"
Carbonated water could be making you put on weight by triggering a "hunger hormone", new research has shown.
Researchers at Birzeit University in the Palestinian West Bank monitored rats' behaviour and weight gain patterns.
They found that rodents put on a diet of sparkling water in the laboratory put on more weight than their still water counterparts.
The rats ate 20pc more on average, according to the research.
The study says that carbonated water increases a hunger hormone called ghrelin, which makes individuals eat more than they would otherwise.
The study also looked at humans who had sparkling water at breakfast and were later found to have six times more ghrelin in their systems.
However, it has been noted that the study is not conclusive - and obesity experts were eager to stress that sparkling water remains a healthier option to reaching for a can of cola or other types of sugary drink.
The British Soft Drinks Association said that were was no scientific evidence that the carbon dioxide in drinks causes increased hunger, and therefore increased calorie consumption.
In fact previous research found the opposite - as a Japanese study found that the fizz in carbonated water helped people feel fuller for longer.
And a 2002 trial on patients with frequent dyspepsia or constipation found that after 15 days, both conditions improved in the people drinking sparkling water.
There was no improvement in those drinking tap water over the same period, according to the 'European Journal of Gastroenterology and Hepatology'.