There is conflicting information in the Fallout universe on whether the ghouls need to eat and drink to survive.
In Fallout 1, if you
steal the ghouls' water chip and do not repair their water pump, the ghouls will die of thirst.
In Fallout New Vegas, the ghoul Harland claims to live off radroach and condensation, implying that ghouls need food and water to survive.
However, in Fallout 4, the ghoul Billy Peabody
claims to have been trapped in a fridge since the Great War (for 210 years), which means that he did not need food and water to survive for 210 years.
Do ghouls need food and water to survive? Is there any canonical information to support or refute either theory?