Pi gu is an ancient Taoist method of fasting for spiritual and healing purposes. Unlike traditional fasting, you do not need to stop eating when practicing pi gu. Used by ancient Taoist masters during their months or years of solitary retreat in pursuit of enlightenment, the practice centers on a simple diet of fruits, teas, nuts, and eggs paired with special chewing techniques and chi kung exercises. Providing a step-by-step guide to Pi Gu Chi Kung, Master Mantak Chia and coauthor Christine Harkness-Giles explain the pi gu diet, provide immortality tea recipes, detail the pi gu chewing exercises, and illustrate the corresponding chi kung energy exercises. They also explain the use of pi gu during darkness retreats to enhance spiritual awareness and increase mental powers and wisdom.