What is Bigu 辟谷?

Bigu, also known as "quegu", "duangu", "juegu", "xiuliang" and so on, refers to abstaining from grains,fasting. Taoists believe that "Bigu" is a method to cultivate into immortals. Taoism holds that when people eat grains, feces will accumulate in the intestines, producing foul qi, which hinders the path to becoming immortals. For this reason, Taoists imitate the behavior of immortals described in Zhuangzi·Xiaoyaoyou as "not eating grains, but inhaling wind and drinking dew", hoping to achieve the goal of immortality.

The Bigu technique originated in the pre-Qin period, roughly at the same time as the qi-circulating technique. Da Dai Li Ji·Yi Ben Ming, a work compiling etiquette before the Qin and Han dynasties, states: "Those who eat meat are brave and fierce; those who eat grains are wise and skillful; those who eat qi are divine and long-lived; those who do not eat are immortal and spiritual." This is the earliest theoretical basis for the Bigu technique. Huainanzi·Di Xing Xun also has similar records. After Taoism was founded, it inherited this technique, and there have been no lack of people practicing Bigu from generation to generation. From the Han Dynasty to the Song Dynasty, the Bigu technique was very popular within Taoism.