Why is smoking forbidden while soft drinks and other harmful foods are permissible, and what is the difference between them even though both are harmful?

If experts prove that consuming a certain food causes harm, then it is not permissible to consume it, even if it is originally permissible (halal (definition)). This is because the fundamental principle regarding foods is permissibility, unless they contain harm. The considered harm is that which leads to the destruction of souls or organs, or the disabling of sensory functions, or affects the mind or body with illness or extraordinary hardship. Jurists have explicitly stated the prohibition of every pure substance that contains harm, whether the harm is inherent in the substance itself, like poison and smoke, or results from its combination with another food, or due to specific health reasons pertaining to the individual. Harm thus negates permissibility. Smoking is unequivocally prohibited due to the conclusive proof of its severe harm.