Currently, it is possible to bring zero food on all of the near-Earth crewed missions, as astronauts survive without food for thirty days.
Not bringing any food on missions is behaviour that should be discouraged. I suggest that the limit for days without food should be lowered significantly.
Currently, kerbals survive without water for three days. This limit means most early crewed missions to LEO also do not require you to bring any water.
Should the limits of both be lowered to something like twenty-four hours? Or would three days for both be preferred?

I think, to discourage not bringing any food and water, twenty-four hours without them should be the limit.

The relevant configs are here: