What I’m guessing the idea here is that nicotine suppresses appetite. In my youth (long long time ago), there were lots of women who were maintaining their slim physique by having a coffee and cig for lunch, for example. I did it when I was a broke student, because cigs were cheaper than food at the time :) I don’t know if someone actively uses nicotine to maintain weight nowadays, in general people smoke less, even in Europe.