Some 1,600 prisoners are taking part, Palestinian Authority Prisoners' Affairs Minister Issa Qaraqe said. More prisoners may join the hunger strike, which was planned to coincide with Palestinian Prisoners' Day, Qaraqe said.
Qaraqe urged Palestinians to support the strike and called on human rights organizations to press Israel about conditions in prisons.
The hunger strike is a way of "bringing prisoners closer to their basic rights and demands and preventing the occupation from harming the dignity of the Palestinian prisoners," he said in a statement.
a high-profile prisoner who enjoys broad support among Palestinians in the West Bank and Gaza, called for the "Freedom and Dignity" strike. Many Palestinians see Barghouti as a potential future leader of the Palestinian Authority, despite his prison sentence.
Palestinian leaders, including Prime Minister Rami Hamdallah and Palestinian Liberation Organization Executive Committee Member Hanan Ashrawi, have backed the strike.
Official: Largest Palestinian prisoner hunger strike ever
The hunger strikers' long list of demands includes an end to solitary confinement and administrative detention, a policy under which Israel holds prisoners without charge or trial.
Some 740 Palestinians are held in administrative detention, Qaraqe said. Prisoners are also demanding better medical care and extended visits with family.
This hunger strike is the largest Palestinian prisoners have ever launched, said Ghassan Khatib, a Palestinian politician and former vice president of Birzeit University. Palestinians have often resorted to hunger strikes, mostly to target administrative detentions.
In a letter penned by Barghouti and read Saturday by his wife, Fadwa, Barghouti accused Israel of detaining "thousands of Palestinians every year in a flagrant violation of international treaties and conventions."
He called Israel's military courts in the West Bank an "accomplice in the occupation's crimes through detentions, unjust court sentences, and torture."
A former leader of the Tanzim brigade -- the militant wing of the Fatah political party -- Barghouti was convicted in 2004 of five counts of murder, including orchestrating attacks against Israelis. He is serving multiple life sentences.
Despite -- or perhaps because of -- his prison sentence, Barghouti's popularity has grown among Palestinians, and he is one of the few Palestinian leaders with support from both Fatah, which governs the West Bank, and Hamas, which rules Gaza.
In Fatah's most recent conference, held in November, Barghouti was elected to the Fatah Central Committee and the Revolutionary Council, pulling in more votes than any other candidate. Given his prison sentence, both are symbolic gestures but are testament to his popularity.
Despite recurrent infighting between Palestinian factions, prisoners from multiple groups, including Hamas and the Palestinian People's Party, are also taking part in the hunger strike.
Israeli official: We don't negotiate with prisoners
A spokesman for the Israel Prison Service, Assaf Librati, said the prison service does not, as a rule, negotiate with prisoners.
The prison service has begun separating hunger strikers into separate cell blocks. Prisoners have so far declared strikes in eight Israeli prisons.
"Hunger strikers in prison endanger the health and life of the prisoners in custody of the state who is in charge of their well-being -- organized hunger strikers even more so," Librati said.
Librati estimated that 1,100 prisoners were participating in the strike, a number lower than that reported by the Palestinian Authority.
Authorities will set up a field hospital at the Ketziot prison in southern Israel to treat hunger strikers if needed, Librati said.
The move would allow Israel to sidestep civilian hospitals, which have so far refused to force-feed strikers, despite an Israeli law passed in July 2015 that legalizes the force-feeding of prisoners.
Responding to accusations of mistreatment in Israeli prisons, Israeli Foreign Ministry spokesman Emmanuel Nahshon fired back.
"The Palestinian prisoners are not political prisoners," he said. "They are convicted terrorists and murderers. They were brought to justice and are treated properly under international law."