“These days, people have changed their way of life. They drink wine as though it were water, indulge excessively in destructive activities, drain their jing – the body’s essence that is stored in the Kidneys – and deplete their (energy).
“They do not know the secret of conserving their energy and vitality. Seeking emotional excitement and momentary pleasures, people disregard the natural rhythm of the universe. They fail to regulate their lifestyle and diet, and sleep improperly. So it is not surprising that they look old at fifty and die soon after.”
Maoshing Ni, The Yellow Emperor’s Classic of Medicine: A New Translation of the Neijing Suwen with Commentary