As of Wednesday, 2,326 inmates were refusing their meals as part of a protest over solitary confinement conditions now on its 11th day, the Los Angeles Times said.
Two inmates have been sent to the hospital for health checks, prison officials said, but there have been no reports of serious medical complications.
Prison officials said they do not plan checkups for most protesters until they have refused meals for 14 days, the Times said.
Lawyers for the 14 inmate leaders said the move has cut off their clients' access to television, radio and the communications network they have created.
Prison investigators also took legal papers from some of the transferred inmates, including a document on an inmates' potential settlement terms, one of the lawyers, Anne Weills, alleged.
Department spokeswoman Terry Thornton said any materials taken from the inmates were returned unread, and that the prisoners have been warned that a hunger strike could bring consequences.
"They should allow their lawsuit to take its course and not be protesting," she said.