Here's an interesting article published in the Talking Crochet Newsletter.
A group in England actually use crochet as an activity for their "Wellbeing Wednesdays." For those of us that crochet, we know that crochet is a relaxing hobby. But not many think about the fact that it keeps our hands busy, which means that we're less likely to be snacking. I know that I tend to eat less when I'm working on a project.
Furthermore, what about smoking? I assume crochet could have similar effects (i.e. helping people quit or smoke less). Since I don't smoke, I am not sure about this one, but it seems like a logical leap to me.