Warning: This is 3.0 Edition material. It is possible that there is more recent 3.5 Edition version.
Inaccurate?

Sustain

(Oriental Adventures)

Transmutation
Level: Shaman 4, Sohei 4,
Components: V, S, M,
Casting Time: 1 round
Range: Touch
Target: Up to one living creature touched/two levels
Duration: 6 hours/level
Saving Throw: None
Spell Resistance: Yes (harmless)

The recipients of the spell can go without food or water for the duration of the spell, feeling no hunger and suffering no ill effects from the deprivation.
An affected creature can eat or drink normally without difficulty.
When the spell ends, the creatures must resume normal eating and drinking habits, but do not feel any adverse effects from the missed meals.
The size of the creature is not a factor; a tiny lizard and a dragon are both fully nourished by the spell.
If a target of the spell is suffering from hunger and thirst, the spell relieves the creature as if it had eaten one healthy meal for every 6 hours of the spell's duration.
Material Component: A flask of warm sake and a rice cake.

Also appears in

  1. Book of Exalted Deeds