Instead of attempting all this social engineering with higher taxes on cigarettes, fast food, sodas and so on, why don't we just remove the barriers employer's, insurers, and for that matter medicare faces to actually pricing coverage based on the risks associated with ones life choices.
For example, instead of taxing sodas more, why not just allow employers to charge obese employees more for their health coverage? Right now, you can be a 300 pound smoker and pay the same rate for your healthcare through your employer as a fit employee that exercises daily. In effect, your poor life choices are simply subsidized by them. The same is true with Medicare. If your overweight or a smoker, statistically your going to cost to the system far more in the future than a non-smoker and fit individual, so why not increase their payroll taxes to pay for the costs of their lifestyle choices rather than passing them on to others that made better life choices.
It seems to me that makes a lot better sense and would be a lot more effective than all these social experiments in the form of "sin taxes" we have now are.