I said that in order to change health behavior, we need to recognize its dangerousness. However, there are many factors to recognize it, for example, timing is the one factor to recognize dangerousness of smoking. If you see an image that tells harmfulness of smoking when you try to smoke, what do you feel? I guess it can make a chance to hang back. Therefore, in Europe that kinds of threatening images are on cigarette box. In every country, warning statement is box distinctly at least.
Thinking of the other, there are many chances to persuade people who is doing harmful act to their health.