They don't teach that it's literally physically flesh and literally physically blood, it's still wine and a bread cracker thing, it's just that they also now have the spiritual essence and properties of the J-man's divinity. Like, most catholics would be confused that anyone would draw a comparison to say cannibalism, because it's not literal in the physical sense, just the spiritual. Which admittedly probably doesn't make much sense unless you're catholic.
Source: raised in catholic town by catholic family with twelve years of catholic school in which I actually read the bible and the catechism, all of which explain why I'm an atheist. But it's funny seeing all the (admittedly understandable) misconceptions people have about what catholics believe.