1, chewing for a long time helps digestion, so energy is supplied for other exercises. 2, it provides the driving force to treat all diseases because chewing for a long time helps digestion. 3, the more you chew, the more saliva comes out. Saliva digests more than 50 percent of the food we eat. Especially in the case of grain, it digests more than 70%. Saliva is the world's least side-effect nat..