|Here's something to chew on: most employees are entirely capable of chewing gum and handling any number of job responsibilities at the same time. If they are incapable of doing so, perhaps you should take a look at your hiring practices.|
It is possible that school children might be distracted by chewing gum, especially when it comes to adding new pieces, blowing bubbles, cracking the gum, or disposing of the used pieces. Having these kinds of problems or a used gum plantation on the bottom of the chairs and desks can be problem in schools, but presumably not in your company.
If you prohibit gum in your meetings, you are going to annoy the employees and make yourself look foolish at the same time. Ironically, your prohibition is likely to be a real distraction.
Instead of focusing on what goes into your employee's mouths during these meetings, it will make more sense to focus on what comes out of their mouths, especially in terms of their inputs, ideas, and suggestions. Chewing gum is not going to interfere with such contributions, but your anti-gum chewing policy might.