That's about the same number as before the release of a video Israel claims shows the strike leader secretly eating in his cell.
Supporters of Marwan Barghouti say the video released earlier this week and purportedly showing him snacking is a fabrication intended to break the prisoners' morale.
The strike entered its 24th day on Wednesday, with prisoners demanding better conditions.
Israel Prison Service spokeswoman Nicole Englander says of the 882 prisoners still participating in the protest, one has been hospitalised and another underwent medical checks.