Triple-killer Stephen Griffiths is now refusing to drink as well as eat, it was reported today.
The self-styled Crossbow Cannibal, who turned 41 today, was jailed for life on Tuesday after he admitted murdering Bradford prostitutes Susan Rushworth, Suzanne Blamires and Shelley Armitage.
A judge at Leeds Crown Court told him he will never be released from prison.
Before he appeared on Tuesday sources confirmed Griffiths had been refusing to eat at the maximum security Wakefield Prison - apparently in protest about being held on his own.
When he was brought into the dock he looked much thinner than he had done at previous court outings.
According to The Sun today, Griffiths is now refusing to take fluids as well as food.
A Prison Service spokeswoman said: "We do not comment on individual prisoners.
"We take food refusal extremely seriously.
"If a prisoner chooses to refuse food for any reason, the Prison Service works with healthcare staff to monitor their physical and mental health.
"Prisoners who are considered mentally capable are entitled to refuse health interventions like force-feeding, provided they fully understand the consequences of their decision."
Griffiths was jailed for life and given a whole life tariff by a judge who heard shocking details of how he killed, dismembered and even ate parts of his victims at his flat near the centre of Bradford, West Yorkshire.
Since he arrived on remand at Wakefield Prison - home to some of Britain's most notorious killers - he has been treated for a number of "self harm" incidents.
Detectives have always said they do not believe he killed any more women but have now broadened their inquiry to liaise with missing persons investigations across the UK.
The dismembered body of Miss Blamires was found in the River Aire at Shipley, West Yorkshire, along with a small part of Miss Armitage. Miss Rushworth's body has not been found.