When Lǐ Qīngyún 李清雲 was 105 years old, he traveled to Pingliang County in Gansu to collect herbs. In the Kōngtóng mountains, Li met a Taoist hermit who was much older than he. Li asked the elder for the secret of long life and the old hermit laughed, saying, “Why are you asking me? Aren’t you doing quite well on your own?”
“Ren Shen參, Zhu Ling猪苓, Ling Zhi靈芝, and the orchid are herbs of longevity,” the hermit said. “The mountains, forests, and the wilderness are all places of quietude. Nature is the secret of longevity, and you have all of this, so why are you asking me?” But Li was persistent, even begging the elder. The old hermit spoke of some breathing [Qigong] and a word of dietary advice to follow.
After his encounter with the elder, Li recruited three Taoist adepts to go to Emei Mountain, a famous Taoist mountain in Sichuan province, to live in practice of these ways. There, Li built a hut and taught the methods to the others. According to Li, within a few years he was able to abstain from grains [bìgǔ 辟谷], learning to lighten the body.
Exercises practiced every day, regularly, correctly, and with sincerity, Li was able to achieve the power of Bìgǔ, attested to by the brightness of his eyes and the sharpness of his senses. He was full of energy, exceeding his former self. At that time he was already 140 years old, but the people who met him said he looked like he was in his 40s.
Li remained at Mei Mountain for about 100 years. The number of his followers grew to around 100; all baby-faced, white-haired elders, each over 100 years old. After the Manchu dynasty ended and the republic was born, Li decided that he was quite old now and decided to move to the Chen Compound in Kaixian 开縣.
What annoyed Mr. Li was that living in the town was just too noisy and there were too many social functions. Some people there challenged him, openly telling him that they did not believe him to be 250 years old. He showed no sign of anger, but his answer on one occasion revealed his displeasure. “Why should I tell a lie?, he said. “It’s up to you whether you believe it or not. If you believe I have lived 250 years, it doesn’t benefit me. If you don’t believe, it doesn’t hurt me. But I have to tell you, during my life I have never lied and I have never cheated.”
http://en.wikipedia.org/wiki/Bigu_(avoiding_grains)