The saying that drinking tea after meals promotes digestion first came from Tea Classic. Hao Rui's Daily Materia Medica in Yuan Dynasty recorded "relieving boredom and quenching thirst, relieving boredom and clearing heart". This shows that tea is a kind of drink that helps digestion and regulates fat metabolism. Digestive function in a broad sense refers to the function on the whole digestive system.

Second, the saying that drinking tea after meals promotes digestion first came from Shennong Herbal Classic. Shennong's Classic of Materia Medica is divided into three volumes, containing 365 kinds of drugs. It is divided into three categories: upper, middle and lower, and its conciseness has become the essence of Chinese medicine theory. Shennong Herbal Classic records the curative effects of 365 kinds of drugs, most of which are true and reliable, and are still commonly used in clinic. It puts forward the idea of dialectical medication. The indications of drugs can reach 170, and there are specific regulations on dosage and time, which also plays a role in traditional Chinese medicine.