Kashrut
Among the numerous laws that form "kashrut" are prohibitions on the consumption of certain animals (such as pork and shellfish), mixtures of meat and milk, and the commandment to slaughter mammals and birds according to a process known as "shechita". There are also laws regarding agricultural produce that might impact the suitability of food for consumption.
Nativity Fast
In the Eastern Orthodox Church, the fast traditionally entails fasting from red meat, poultry, meat products, eggs, dairy products, fish, oil, and wine. Fish, wine and oil are allowed on Saturdays and Sundays, and oil and wine are allowed on Tuesdays and Thursdays, except in the Ethiopian Orthodox Tewahedo Church.