While I agree that everyone would be better served by quitting smoking, I also think there are far more egregious vices than cigarettes.

From what I've read, nicotine, if anything, speeds up one's metabolic rate. So, smoking if we follow the logic here, should be conducive to weight loss, if anything.

However, as someone has pointed out, the risks associated with cigarettes would most likely far outweigh any calorie equilibrium benefits gained.

Yet again, there are lots of other things around which harm us, not just cigarettes.