Alternatively, it might weaken your teeth, in a similar way as being in space weakens your bones, while running helps build bone mass.
If you have to chew gum to make up for this, you're starting to lose the simplicity which was one of the idea's main selling points. A bit like switching from cycling to work to driving to work to save 10 minutes, then having to spend an hour in the gym to make up for the lack of exercise.
I can't help thinking there will turn out to be many more subtle effects to compensate for. Yes, I am a sceptic.