Be warned though, that as you are merrily chewing away the brain thinks "Ah, I'm chewing, therefore some food will be coming soon, better get the stomach ready". Thus your body starts producing hydrochloric acid in the stomach. If nothing arrives (ie you spit out the gum) it starts to digest anything it can find (like the stomach!). Whilst the stomach is lined with an antiacid lining to protect it, it can eventually start to breakdown if you are a regular 'chewer' which can lead to stomach ulcers. So it is always best to eat something, if not the gum.