Answer
When we call the body of Christ "bread" we echo Jesus’ own words, "I am the living bread which came down from heaven" (John 6:51).
This expression is but one of many which call forth the various.aspects of the Eucharist. The Catechism of the Catholic Church explains:
The inexhaustible richness of this sacrament [of the Eucharist] is expressed in the different names we give it. Each name evokes certain.aspects of it. It is called . . . the Breaking of Bread, because Jesus used this rite, part of a Jewish meal, when as master of the table he blessed and distributed the bread, above all at the Last Supper. It is by this action that his disciples will recognize him after his Resurrection, and it is this expression that the first Christians will use to designate their Eucharistic assemblies; by doing so they signified that all who eat the one broken bread, Christ, enter into communion with him and form but one body in him. (CCC 1328-1329)