Catholics do not believe that the Holy Eucharist is literally the Body and Blood of Jesus. If it were literally so, there would be visible human flesh and blood on the altar. More accurately, Catholics believe in the true and real presence of Christ in the consecrated elements of bread and wine. They are really and truly transubstantiated (changed in substance) into his Body and Blood in all but appearance.
Some Catholics may not believe this but the canon of the Catholic church does.
Council of Trent, Canon 1 of the Thirteenth Session, "If anyone denies that in the sacrament of the most Holy Eucharist are contained truly, really and substantially the body and blood together with the soul and divinity of our Lord Jesus Christ, and consequently the whole Christ, but says that He is in it only as in a sign, or figure or force, let him be anathema."
This canon directly condemns the denial of the true, real, and substantial presence of Jesus Christ, including His body, blood, soul, and divinity, in the sacrament of the Eucharist after the consecration. It specifically rejects the idea that Christ is present only symbolically ("as in a sign, or figure or force"). The consequence for holding such a belief, as decreed by the council, is anathema.