Which soft drinks are safe to drink and what's maximum amount for drinking soft drink a day?

There are two types of soft drinks, one made with real sugar and one made with corn syrup. You can't stand to drink more than two cans of corn syrup. The real sugar drink will leave you craving more. Both of them have zero nutrition, other than the calories. The real sugar tends to crystallize on your teeth.

Why are you even considering such a question?