Gong Tingxian, a famous doctor in Ming Dynasty, lived to be 92 years old. The Poem of Health Preservation written by him is a set of scientific laws about "eat, drink and be merry" on the basis of many years' practice of treating diseases and keeping in good health. The full text of this poem is as follows:

Cherish the essence of gas reservoir is more nourishing,

Don't worry about thinking less, thinking less.

Only half full and tasteless,

Don't overdo it after three minutes of abstinence.

Make fun of every joke,

Often contains an angry will.

Don't even ask if it's cold or not,

Let me live happily for a hundred years.