Three meals a day, eating on time, is related to the biological rhythm of the human body. Three meals a day are carried out in the morning, noon and evening, respectively. During these three times, the digestive enzymes in the gastrointestinal tract of the human body are particularly active, which is ready for digesting food. Eating at this time is very conducive to food digestion and absorption. When to eat is related to the adjustment of the biological clock of the human body. Once disturbed, the function of the gastrointestinal tract will be affected first.