Interesting! Chewing gum always seems to fill that psychological need for a snack even when I'm not actually hungry. Years back my naturopath mentioned that chewing tells the brain and gut to speed up digestion because it tricks them into expecting more food coming down.
Three years back I gave up cigarettes. These days I keep sugarless gum around to chew. The other day I ran into a write-up that caught my eye. It described research on how chewing changes GLP-1 amounts in the blood among men who had skipped meals, stayed fit, and carried no extra weight. They asked participants to chew the gum so they could look at nerve signals that control release of that hormone after the men went half a day without food.