Food usually stays in the stomach for 6-8 hours, which means there must be an interval of 8- 10 hour between meals. Eating two meals a day can give the stomach a full rest and prepare for the next digestion: storing enzymes, secreting mucus, repairing gastric mucosa and restoring the contraction function of digestive system. When the stomach digests food, especially food rich in protein, cells will produce a lot of hydrochloric acid, mucus and gastric enzymes. Although these are the main components for decomposing protein and other compounds, they can cause damage to the stomach wall. Therefore, compared with other digestive organs, the stomach needs to rest for a longer time. Will automatically adjust to different dining habits.