As far as I understand a VQ is an extended period of aloneness in nature, without distractions such as radio, TV, books, fancy foods or an overabundance of foods, etc. The chosen environment and conditions allow realizations to surface which we usually keep under wraps.

Any very serious deprivation will result in self-preoccupation, anxiety and maybe panic. This will stall the processes a VQ is designed for.
VQ's are not survival courses, although the food supply may be such that one is encouraged to supplement it with what can be found.