I hate to challenge the superior wisdom of the Irish mother, but something about this hasn’t sat right with me for years.
It’s an undeniable law of physics that flat fizzy drinks taste pure mank, like. And I know that medicine isn’t supposed to taste nice (except purple calpol, of course), but flat fizzy drinks are not medicine.
The myth is that the drink will help with rehydration and will be easy on the stomach, but the Daily Mail reported in 2008 that:
Flat cola or other drinks are not an effective substitute for oral rehydration solutions, which contain the right balance of salts and sugar, experts warned.
Not only that, but it turns out they can actually be BAD for children with stomach bugs. This is according to NHS doctors in the UK circa 2009 (Daily Mail again).
Our mothers lied to us! The upside to all this, of course, is that we got to drink flat 7up instead of “oral rehydration solutions”.