On the empty, artificial Enterprise of the planet Gideon Kirk offhandedly assures Odona that food is not a concern. "Power, that's no problem. It regenerates. And food? We have enough to feed a crew of 430 for five years. So that should last us forever." (How the overpopulated inhabitants of Gideon fed themselves remains an unsolved riddle of the episode.) On normal patrol a starship could be expected to replenish supplies at regular docking intervals with other ships or starbases, or even vice versa as with Kirk's delayed delivery of chili peppers to Commander Dominguez.

It's not unreasonable that trips to bountiful planets would include restocking away teams as well, but that couldn't help Kirk and Odona. Presuming only the two of them were available Kirk's answer rules out any substantial amount of human labor necessary to prepare food. It becomes a question of material resources only.

Those resources are either completely recycled, completely unrecycled, or somewhere in between. The first two of these cases allow some bounds to be computed. A minimal estimate of daily human consumables allowing for nutrition and calorie intake would be 641g of dry food and 2845g of water, not including water for hygiene. For a crew of 430 that's 276kg of food and 1.22kl of water per day. Let's assume 23rd century recycling techniques can't replicate faster than daily. No one is eating their lunch - or anybody else's - for dinner!

(All of this avoids the issue of any food grown aboard a starship. There's no doubt Enterprise has galleys and gardens so there's no reason crewmembers inclined to grow food couldn't do so, subject to space limitations. At present best estimates for minimal agricultural surface area to sustain one human is between 20 and 2500 square meters. An analysis of self-sustenance, waste and gas exchange requirements is postponed to the next part of this series.)

With non-recycled food processing (all prepackaged, frozen and stowed somewhere "belowdecks") that comes to 503mt of food and 2234mt of water for the entire five year mission. Enterprise masses 190000mt so human consumables would come to about 1.4%, a rather large proportion. It's reasonable that water filtration is much more efficient but also true that dry food prep would require additional water, but that figure establishes that at least it's not impossible.

Yet no matter how sanitary the process becomes, how sterile the high falutin' physics of molecular replication, unwrapping and zapping one's meals still sounds better than eating yesterday's breakfast over, and over, and over again.