I agree that if food is found clearly to be unhealthy, it should be avoided, but i do not think one should alter their habits regarding communally accepted practices, like eating cholent and kugel.
Shomer pesayim would likewise permit, but not recommend, things like soda; i was saying that to forbid it would be against halacha.
Smoking at this point might be assur, not because of current knowledge but because it’s fallen out of practice.