Activists at the University of Manchester said the strike, which began on Thursday, would last for at least one week.
More than 1,500 Palestinian political prisoners, led by senior Fatah figure Marwan Barghouti, are refusing food to raise awareness of abuses by Israeli authorities.
Talking to Al Jazeera on Saturday, Mohammed Ezzeldin, one of the five UK students on hunger strike, explained his reasons for participating.
"Political prisoners in Palestine are being held for up to six months without charge or fair trial," he said.
"They are facing abhorrent conditions in jail, with no access to medical treatment or visitation rights."
Ezzeldin said he hoped the hunger strike would also pressure the university into dropping disciplinary action against two students involved in an anti-Israel protest in March.
"While we've gone on hunger strike purely in solidarity with the Palestinian political prisoners, we hope it increases pressure on the university to comply with our demands.
"Those are to drop all charges from the disciplinary hearing of the two BDS [Boycott, Divestment, and Sanctions] campaign activists."
The pair are accused by the university of trespassing and damage to property after unfurling a banner expressing support for the BDS movement.
Palestinian activists accuse the university of censoring criticism of Israel and are demanding that it drop the case.
On Thursday, hundreds of students at SOAS protested against a visit by the Israeli ambassador to the UK, Mark Regev.