How did he do it?
Ching-Yuen is reported to have lived off a diet of herbs and rice wine inculding lingzhi, Goji Berries– wild ginseng, he shou wu and gotu kola.
Where is the proof?
In a 1930 New York Times article, Professor Wu Chung-chieh of the University of Chengdu found Imperial Chinese government records from 1827, congratulating Li Ching-Yuen on his 150th birthday. Further documents later congratulate him on his 200th birthday in 1877. (Wikipedia 2013). http://en.wikipedia.org/wiki/Li_Ching-Yuen