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.
Break fast
Orthodox Jews generally do not eat meat or drink wine at the break-fast after Tisha B'Av because the burning of the Temple on the 9th of Av is said to have continued until noon on the 10th of Av. Even when the 9th of Av falls and Shabbat and Tisha B'Av is observed on the 10th, though all other Nine Days restrictions end with the fast, wine and meat are customarily still not consumed at the break fast.