Macrobiotics (from the Greek for "long life") is a diet and lifestyle created originally by Japanese writer and guru Nyoichi Sakurazawa, better known under the pen name Georges Ohsawa, and popularized in Western countries by his student Michio Kushi and others. Essentially, the macrobiotic way proposes to break the foods consumed by human beings down into yin and yang according to some arbitrary scheme, then balance out the diet into yin and yang foods and thereby achieve significant life extension.
While meat is not banned from macrobiotic meals, it falls into the category of foods that are "extremely yang", i.e. "stagnating", while alcohol, fermented foods, and some spices are considered "extremely yin" or "overstimulating". Many macrobiotic practitioners are therefore either partially or wholly vegetarian. Much macrobiotic food tends to be essentially vegetarian Japanese food, though that need not be the case.
Oddly enough, despite its claims to promote longer lives, neither the founder, Ohsawa, nor Michio Kuchi's wife Aveline (a noted author in the macrobiotic movement in her own right) had a longer than average lifespan; Ohsawa died of heart disease at age 72, and Aveline Kushi of cervical cancer, even as Ohsawa promoted macrobiotics in part as a cancer prevention diet.
While Ohsawa focused on diet as a means by which to promote health, he was a heavy smoker. He even stretched macrobiotic precepts to suggest that the blue or gray smoke coming out the front of a cigarette is yin (cancer-causing), while the yellow or orange smoke coming out the back that the smoker breathes in is yang, which obviously flies in the face of all we know about the dangers of smoking. 
 See also
- Skeptic's Dictionary entry
- Description at Quackwatch.com, specifically related to cancer treatment
- Account of a Michio Kushi-led seminar at Quackwatch