You don't even have to swap to water. Sugar free drinks are extremely good replacements for full sugar drinks.
Do that enough over a long enough period of time, and your body starts to become immune to the insulin it produces. And you become a Type 2 diabetic. And as a T2 diabetic, it becomes very easy to put on weight and very hard to lose it.
That’s not the only mechanism for becoming a T2, but it is a key one.
This article from a Dr does a pretty good job of clarifying. https://www.imaware.health/blog/artificial-sweeteners-and-in...