How does Roman Catholic teaching describe the real presence of Christ in the Eucharist?

In Roman Catholic theology, the real presence of Christ in the Eucharist is understood through the doctrine of transubstantiation.12

This teaching asserts that during the consecration of the mass, the substance of the bread and wine is converted into the actual substance of the body and blood of Christ. While this change occurs at the level of substance, the outward appearances—referred to as accidents—remain unchanged.13

The Catholic Church maintains this doctrine to safeguard the literal truth of Christ’s presence while emphasizing that there is no empirical change in the bread and wine. Although some 20th-century theologians explored alternative interpretations like transsignification or transfinalization, the Magisterium, notably through Pope Paul VI in his encyclical Mysterium fidei, reaffirmed that the dogma of the real presence must be expressed through the terminology of transubstantiation. This belief is intended to highlight the intimate relationship between Jesus and the communicant.21