I would recommend watching 28 Days Later and then 28 Weeks later. What happens in them is that this virus called "rage" basically turns people into cannibalistic psychos (Zombies?). Not enough explanation but i recommend you watch it to find out more about it.
hmm... saw 28 days yesterday, but I can't remember that these are cannibalistic psychos.
The people infected with rage do just kill the people (by biting or doing other stuff), but I absolutely can't remember to have seen anyone eating his victim.
As this military guy says: It is only about people killing people.
But anyway, great movies and a must to watch if not watched yet :)