Smoking is significantly worse for you and your family than obesity. It causes a greater reduction in life expectancy, and can impact the physical health of those who live or work with you via secondhand smoke.

It is simply wild how many ways nicotine can find to kill humans. All kinds of stuff stems from the lowly cigarette. Obesity impacts many more people (that is to say, we have more fat people than smokers/tobacco users), but it's far from as significant a health risk. I'm not sure we know enough to quantify vapes and chew vs. obesity.