Early history The first vegetarians in written western history may have been the
Pythagoreans, a title derived from the Greek philosopher
Pythagoras. Though Pythagoras loaned his name to the meatless diet, some biographers suspect he may have eaten fish as well at some points, which would have made him not a vegetarian but a pescetarian by today's standards. Many of Pythagoras's philosophies inspired
Plato, who advocated for the moral and nutritional superiority of vegetarian-oriented diets. In Plato's ideal republic, a healthy diet would consist of cereals, seeds, beans, fruit, milk, honey and fish. In 675, the consumption of
livestock and wild animals, with the exception of deer and wild boar, was banned in Japan by
Emperor Tenmu, due to the influence of Buddhism and the lack of arable land. Subsequently, in the year 737 of the Nara period, the
Emperor Shōmu approved the eating of fish and shellfish. During the 1200 years from the
Nara period to the
Meiji Restoration in the latter half of the 19th century, Japanese people ate vegetarian-style meals, and on special occasions, seafood was served. Exceptions were wild fowl served amongst the Heian nobility, and when Europeans arrived in Japan in the 15th century, the Japanese diet included boar meat. Several orders of
monks in
medieval Europe restricted or banned the consumption of meat for
ascetic reasons, but none of them abstained from the consumption of fish; these monks were not vegetarians, but some were pescetarians.
Marcion of Sinope and his followers ate fish but no fowl or red meat. Fish was seen by the
Marcionites as a holier kind of food. They consumed bread, fish, honey, milk, and vegetables. The "Hearers" of the ecclesiastical hierarchy of
Manichaeism lived on a diet of fish, grain, and vegetables. Consumption of land animals was forbidden, based on the Manichaean belief that "fish, being born in and of the waters, and without any sexual connexion on the part of other fishes, are free from the taint which pollutes all animals". The
Rule of Saint Benedict insisted upon total abstinence of meat from four-footed animals, except in cases of the sick.
Benedictine monks thus followed a diet based on vegetables, eggs, milk, butter, cheese, and fish.
Paul the Deacon specified that cheese, eggs, and fish were part of a monk's ordinary diet. The
Carthusians followed a strict diet that consisted of fish, cheese, eggs, and vegetables, with only bread and water on Fridays. Ponds were created for fish farming. In 1336,
Pope Benedict XII permitted monks to eat meat four days a week outside of the fast season if it was not served in the refectory.
19th century to present Francis William Newman, who was President of the
Vegetarian Society from 1873 to 1883, made an associate membership possible for people who were not completely vegetarian like pescetarians. Eventually, in the 1890s, Newman himself switched from following an ovo-lacto-vegetarian diet to a pescetarian diet, with the rationale that fish do not waste land space, are plentiful due to high reproduction rates, do not care for their young and have no parental feelings to violate, and can be captured and slaughtered in ways that inflict minimal pain. Interest in pescetarian diets continued to grow into the 21st century, alongside broader trends in plant based eating. Surveys in the 2010s and beyond have found that a small but noticeable segment of populations in Western countries identify with pescetarian or related diets, often citing environmental motivations for reducing consumption of red and processed meats in favor of seafood and plant foods. A 2016 book
Seagan Eating promoted a seafood diet, which is distinguished from ordinary pescetarian diets because it discourages consumption of dairy and eggs. == Trends and demographics ==