Starvation imminent in Mars Base Zero

Actually, barring any unusual health conditions, you might be able to
last for a couple of months with no food (as long as you had water) [but
likely damage your health]. In fact, current research suggests people on
reduced calorie diets live longer. In general, hours or days of fasting
(even a juice fast) may when done properly be good for your mental or
physical health.
http://www.healthy.net/library/articles/naturopathic/art.fasting.htm
http://en.wikipedia.org/wiki/Fasting
Juice fasts (nothing but water or juices) for several days can be fairly
easy to do and help keep the body from burning too much muscle
(obviously check with your doctor first if there are any issues, etc.).
Some people think a prolonged fast kicks the body into scavenger mode
and causes your body to clean up junk lying around in cells. In any
case, knowing what is a needed and healthy amount of food for space
settlers may differ from either the amount of food typical US citizens
eat or the larger amount farmers or athletes eat if they do a lot of
physical labor.

By the way, I forgot to mention this before, but I think there are some
potential issues with excess nitrate production in lettuce or other
vegetables when grown in lower levels of daylight and in enclosed areas
(like a "Solviva" greenhouse). Something to consider long term. See for
example:
http://www.fuzzylu.com/greencenter/rr/rr003.htm
"During midwinter low-light conditions in many greenhouses, nitrate
accumulates in many plants as they take up nitrate but lack the light to
photosynthesize and reduce the nitrate to amino acids. Excessive nitrate
in greenhouse lettuce is a major concern in the Netherlands, and it is
possible that this biofilter configuration is unsuitable for growing
certain leafy food crops in the midwinter if levels of available nitrate
are high (Brinton 1985, Vogtmann et al. 1984)."
See also:
http://www.solviva.com/Greyburg_Greendale-BOOK.htm

Thanks for all the updates, and good luck also on your new project (your
upcoming baby!)

--Paul Fernhout