¹⁰ Includes part of [ref.201]. See also [ref.202].
The human body can use food stores so that the nutritional requirements
can be reduced for a short time. This will vary widely among individuals
and each individual may exhibit characteristic patterns of nutritional
behavior. During reduced food intake, muscular efficiency may not change
significantly over a period of 4 to 6 days; unfortunately, however,
mental activity begins to decline after 24 hours. Feeding requirements
can be divided into two categories: short term (for missions of less
than 21 days) and long term. Since dehydration can occur in a matter of
hours under adverse conditions, water requirements must be considered as
a special case.