Because Buddhism believes that morning is an eclipse of the sky, that is, an eclipse of the heavens; Noon is the time for the Buddha to eat, that is, the time for the third Buddha to eat; Sunset is the time for animals to eat; The faint night is when ghosts and gods eat.

Add a Agama to record the whole story, about "no food after noon":

When the Buddha preached Dharma in the refined house of Swat Garden, he said to his disciples, "I always sit and eat. My body is light and my strength is strong." The so-called sitting to eat is to eat a meal. The Buddha said that this is his way of keeping in good health, and he hoped that the monks would follow his example. Arhat, headed by Postotipolo, replied, "If you eat less than one meal, you will lose your strength.

"The Buddha said," Then you can make a fortune once and eat twice. Postscript Tiboro and others said, "We can't stand it." When the disciple rejected the Buddha's proposal, "the Buddha remained silent."

Extended data

Advantages of not eating after noon:

First, eating less will reduce the desire of men and women.

Second, you can get peace of mind and body and give your stomach a proper rest.

Third, it is easy to enter meditation.

Fourth, have more time to practice enlightenment.

Fifth, if you want to get rid of it, your appetite will be purified.

Buddhists in the Six and Three Dynasties did not eat in the afternoon.

Baidu Encyclopedia-No food after noon