Dozens of Israelis gathered outside the Ofer jail, near Ramallah, and began barbecuing chicken and other meats within close proximity of the Palestinian prisoners.
The men said they hoped the smell of the grilled meat would increase the suffering of the detainees who launched a hunger strike this week, a reporter at the scene said.
A number of Israeli soldiers also joined them to eat the feast.
Over 1,600 Palestinian prisoners launched a mass hunger strike on 17 April to protest conditions in Israeli jails.
Launched on Palestinian Prisoners' Day, it is one of the biggest protests in recent times, with inmates from Hamas and Islamic Jihad also participating in the action.
The hunger strike is being led by Palestinian leader and one of the most high-profile detainees Marwan Barghouti.
He is serving five life sentences over his role in the second Palestinian intifada against the Israeli occupation, and was put into solitary confinement for penning a comment piece for the New York Times, sparking protests.
Some 6,500 Palestinians are currently detained by Israel for a range of offences and alleged crimes. Around 500 are held under administrative detention, which allows for imprisonment without charge.
Palestinian prisoners have mounted repeated hunger strikes, but rarely on such a scale.