I'm a Protestant, but that explanation of transubstantiation may be the popular understanding but is not the actual official doctrine of the Catholic Church. I

I'm a Protestant, but that explanation of transubstantiation may be the popular understanding but is not the actual official doctrine of the Catholic Church. I was raised a Catholic, I believe doctrine changed at some time, maybe Vatican II? I remember being told as a child (a long time ago :) not to eat some time before communion. Maybe that's obsolete now.