"What I heard is that chewing gum sends a message to the brain that you are processing food. And that, in turn, makes the brain release insulin, where its not needed, thinking that food needs to be broken down in the stomach. Under "normal" conditions when you eat food, the insulin released by the brain (throught the pancrease) will
digest the food present in the stomach. This is totally normal and this is how we get the food digested properly etc. BUT when insulin is released UNNCESSARILY, e.g., without food in the stomach to digest, insulin converts into ENERGY that is NOT BURNED in itself causing such maladies as hypogloxemia, or energy that isn't expelled
therefore turns into fat. So what that means is that now we have created unnecessary calories just by chewing gum." -fairkismet