Bigu is a Daoist fasting technique associated with achieving xian "transcendence; immortality". Grain avoidance is related to multifaceted Chinese cultural beliefs. For instance, bigu fasting was the
Shennong tasting plants to discover their qualities
Shennong ploughing fields, Han dynasty mural
Neidan, or internal alchemy, is an array of esoteric doctrines and physical, mental, and spiritual practices that Taoist initiates use in hopes to prolong life and create an immortal spiritual body th
Bigu (grain avoidance)
…Macrobiotic diet Neidan Yangsheng (Daoism…
Mingjing Dandao tu (明鏡丹道圖, 'Bright Mirror of Internal Alchemy') using diagrams to systematically elucidate neidan theory
Chinese woodblock illustration of neidan "Putting the miraculous elixir on the ding tripod", 1615 Xingming guizhi (Pointers on Spiritual Nature and Bodily Life)
Chinese woodblock illustration of neidan "Cleansing the heart-mind and retiring into concealment", 1615 Xingming guizhi