The detainees began the hunger strike Tuesday after some of the Palestinians being held in solitary confinement started a protest against the policy, Press TV reported citing a statement by the Palestinian Prisoners Society.
The strikers also demanded the release of prisoners who were ill, the report said.
A Palestinian prisoner, identified as Nahar al-Saadi, has been refusing meals since Nov 20 to protest against his solitary confinement. He was later joined by two other prisoners.
Reports say over 7,000 Palestinians are being held in Israeli jails, many of them without charge or trial.
The Israeli Prison Service, the agency responsible for overseeing jails, has come under criticism from human rights groups for rampant rights abuses in jails.