It was a sparkling lemonade/soda with zero sugar or calories, but still tasted sweet enough and highly refreshing when cold. Would also accept a replacement for the non-diet version, which in my region of the US was unavailable even before they got rid of the diet version.
There’s tons of diet lemonades. You might be able to buy a diet powder and combine it with a Sodastream (carbonate you own water and then add the powder. Or buy sparkling water and add the powder). Other than that, Orangina comes to mind. But that’s more sparking orange-ade
Interesting ideas! Thank you