Caffeine is a diuretic, but you'd need over 500mg to feel that effect beyond the normal "I drank a ton of water and I need to pee"
There is something to be said for the fact that people who drink a lot of soda will be less likely to drink a regular glass of water, but all sodas, no matter how much caffeine they contain, are mostly water and will still hydrate you.
This isn't actually true.
Caffeine is a diuretic, but you'd need over 500mg to feel that effect beyond the normal "I drank a ton of water and I need to pee"
There is something to be said for the fact that people who drink a lot of soda will be less likely to drink a regular glass of water, but all sodas, no matter how much caffeine they contain, are mostly water and will still hydrate you.
https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/caffeinated-drinks/faq-20057965