To be exact, how much caffeine is there in 1 liter of regular Coca Cola? I read that if you consume around 200mg of caffeine a day or even less if you are more sensitive (regardless of the source, soda, coffe, tea,…), you may get anxiety problems and even panic attacks, and if you consume a lot of it for a long period of time, you get addicted to it and you actually get head aches when you try to stop, of course there is insomnia as well. So sugar may not be nearly as much as of a danger compared to this, yet everyone just talks about sugar related issues.
according to this, just a bit under 100mg in a liter. The values here match values I found elsewhere.