One can be addicted to the nicotine in tobacco (in addition, there is a component to smoking that can be classified as a habit.
However, eating sugar containing substances, or sweets, is a habit, but eating sugars is not classified as an addition.
This is not to say that a "strong," or deep-rooted habit may be a difficult thing to break. It is possible that, psychologically, one crave sugars.
It is not easy to say which is easier to give up, cigarettes or sugars. It depends of the individual, and it will have to be determined on a case by case basis.