We have taxes on sugary drinks in France. The tax depends on how much sugar is added, in kg / hl. Funnily, synthetic sweeteners are also taxed, but at a flat rate equal to the "up to 1 kg / hl" of sugar. See [0] for the official text.

I'm not convinced this has had a great effect, since I hear there are more and more people who are considered obese [1].

[0] https://entreprendre.service-public.fr/vosdroits/F32101?lang...

[1] https://presse.inserm.fr/en/obesite-et-surpoids-pres-dun-fra...