[1][3] Major principles of macrobiotic diets are to reduce animal products, eat locally grown foods that are in season, and consume meals in moderation.
[6] 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.
[10] Macrobiotics emphasizes locally grown whole grain cereals, pulses (legumes), vegetables, edible seaweed, fermented soy products, and fruit combined into meals according to the ancient Chinese principle of balance known as yin and yang.
[13] Brown rice and other whole grains such as barley, millet, oats, quinoa, spelt, rye, and teff are considered by macrobiotics to be the foods in which yin and yang are closest to being in balance.
[14] Nightshade vegetables, including tomatoes, peppers, potatoes, and eggplant; also, spinach, beets, and avocados, are not recommended or are used sparingly in macrobiotic cooking, as they are considered extremely yin.
In 1966, a Grand Jury who reviewed several cases of death from malnutrition among macrobiotic proponents concluded that the diet "constitutes a public health hazard".
[18] In 1971, the American Medical Association's Council on Foods and Nutrition commented that followers of the diet were in "great danger" of malnutrition.
[18] The Kushi Institute was located on a large site in Becket, Massachusetts where it hosted macrobiotic conferences, lectures and seminars.
Kushi combined macrobiotics with numerous paranormal and pseudoscientific ideas including auras, astrology, chakras, oriental physiognomy, palmistry and extra-terrestrial encounters.
[7] The Office of Technology Assessment, examining both published and unpublished macrobiotic literature, failed to verify any claims of cancer cure.
[5] One of the earlier versions of the macrobiotic diet that involved eating only brown rice and water has been linked to severe nutritional deficiencies and even death.
[24] Macrobiotic diets have not been tested in women who are pregnant or breast-feeding, and the most extreme versions may not include enough of certain nutrients for normal fetal growth.