Scripture readings, prayers and an offering, including tithing (money collection), are other standard features. The instruments and forms of worship music vary greatly throughout the worldwide church. Holy Communion Adventist churches usually practice open communion four times a year. It commences with a foot washing ceremony, known as the "Ordinance of Humility", based on the Gospel account of John 13. The Ordinance of Humility is meant to emulate Christ's washing of his disciples' feet at the Last Supper and to remind participants of the need to humbly serve one another. Participants segregate by gender to separate rooms to conduct this ritual, although some congregations allow married couples to perform the ordinance on each other and families are often encouraged to participate together. After its completion, participants return to the main sanctuary for consumption of the Lord's Supper, which consists of unleavened bread and unfermented grape juice. Health and diet Since the 1860s when the church began, wholeness and health have been an emphasis of the Adventist church. Adventists are known for presenting a health message that advocates vegetarianism and expects adherence to the kosher laws, particularly the consumption of kosher foods described in Leviticus 11, meaning abstinence from pork, rabbit, shellfish, and other animals proscribed as "unclean". The church discourages its members from consuming alcoholic beverages, tobacco or illegal drugs since the 1800s (compare Christianity and alcohol). In addition, some Adventists avoid refined foods, sweeteners, and caffeine. The pioneers of the Adventist Church had much to do with the common acceptance of breakfast cereals and meat alternatives into the Western diet. John Harvey Kellogg started the meat alternative movement by creating Protose at Battle Creek Sanitarium, which was later sold through mail order by Battle Creek Food Company. The Battle Creek Food Company mostly manufactured meat alternatives for the guests at Battle Creek Sanitarium. Will Keith Kellogg and John Harvey Kellogg invented corn flakes at Battle Creek Sanitarium, by putting stale wheat berry between rollers and baking it. It was later served to the sanitarium guests. The Kellogg brothers also invented Bran flakes and Rice Krispies. Later in 1906, Will Keith Kellogg founded the Battle Creek Toasted Corn Flake Company in Battle Creek, Michigan. Special Foods founded in Worthington, Ohio in 1939, manufactured nut meat substitutes. After World War II, it changed its name to Worthington Foods. Worthington Foods introduced two canned meat alternatives in 1949: Soyloin Steaks and Meatless