There's a ritual in Divine Power called Iron Vigil:
You invoke your dedication to your god and let it wash your fatigue and needs from you. Iron Vigil fulfills your body's need for food and water when you perform it and allows you to remain aware and alert while taking an extended rest anytime during the ritual's duration.
What exactly does the part in bold mean?
If you feel that it could reasonably be interpreted in multiple ways, then I'd appreciate some insight into the consequences of the possible rulings.