Does chewing gum help to slim your face?

In the vast majority of cases, chewing gum will not affect the shape of your face. If it does create any change it would be increasing bulk (widening) of the masseter and possibly temporalis muscles. If you're looking to slim the lower face, Botox injections can make a dramatic difference in certain people. Stephen Weber MD, FACSDenver Facial Plastic Surgeon

Thank you for your question. Chewing gum will not slim your face - in fact, it is unlikely to affect the appearance of your face at all. If you would like to create a slimmer facial profile, I suggest you schedule a consultation with an experienced, board-certified facial plastic surgeon who can assess you in person and create a customized treatment plan for you. Options might include injections of a neuromodulator like Botox into the masseter muscles to reduce their size and narrow the jawline, or buccal fat pad removal, which surgically removes the small pad of fat in the lower cheek. A qualified provider will be able to determine which of these treatments will meet your needs and goals best.

Thank you for your question.  If chewing gum has any effect on facial appearance it would be to widen it, caused by an increase in size to the muscles responsible for chewing - the temporalis and masseter.  Hope this helps.