The tacit assumption which now prevails, "Astronauts even on short-term
missions require a diet of great variety," is apparently not well
supported. In many parts of the world, people live on a monotonous diet
consisting of only a few types of food with no apparent ill effects,
provided their nutritional requirements are satisfied. Experimental
evidence from many sources (e.g., the Army Medical Research and
Nutrition Laboratory) shows that individuals can be kept on a single
disagreeable formula diet for as long as 60 to 90 days without harm.
Since highly motivated individuals are chosen for space flights, it is
unlikely that they would object to the monotony of a formula diet and
would probably prefer its simplicity. Also, there are definite
possibilities of developing a much more acceptable formula than present
types. There is no reason to anticipate adverse effects from the use of
formula diets in short-term flights.
Formula diets would be extremely desirable for short-term flights. A
formula diet (a rehydrated liquid formula could be used) would
considerably reduce the number of manipulations and the time required
for in-flight preparation, compared to a varied diet. These two
improvements could contribute materially to the safety of a flight,
since the astronauts would not be preoccupied with food preparation for
so long a period, and the food could be dispensed without removing suit
components, such as gloves. Storage requirements could be simplified
with this type of diet. Weight, however, would not be lowered without
the development of more refined formulas than those now available.
Formula diets could readily be adapted to the determined metabolic
requirements of the individual astronaut. Packaging problems will be
simplified by using formula diets, which can easily be given a variety
of flavors and colors.