What ingredient in soda makes you dehydrated?

Question

I'm wondering this because I thought it might be the caffeine, in which case, drinking Sprite wouldn't make you dehydrated, unlike Coke or Dr. Pepper.

Answer 1

Sodium

Answer 2

You're right.  It's the caffeine that is called a diuretic, which is the group name for all substances that cause dehydration.

Answer 3

Caffeine.

Answer 4

many things.  sugar, caffeine or even sodium if it's present.