The macrobiotic diet is associated with Zen Buddhism and is based on the idea of balancing yin and yang. The diet proposes 10 plans which are followed to reach a supposedly ideal yin:yang ratio of 5:1. The diet was popularized by George Ohsawa in the 1930s and subsequently elaborated on by his disciple Michio Kushi. Medical historian Barbara Clow writes that, in common with many other types of quackery, macrobiotics takes a view of illness and of therapy which conflicts with mainstream medicine.