In my younger, smoking years, when the anti-smoking lobby grew stronger and managed to land more and more restrictions on smoking, to the degree that you almost felt like a leper... I remember telling my anti-smoking, chocolate-eating friends “you know one day they will come for you too, right?” That sure didn’t take long. Let’s see how they feel about it this time around.
Smoking is banned for under 18 already, and affects others around you, while chocolate does not (an I really saying this?). As seen in the article, sugar is a bigger issue for the 4-18 age range. I’m sure your friends feel absolutely fine.