Food? Hum. Well I guess that depends on the type of ship we take and the amount of space we have to produce our own food.
As a space ship is an indoor self-contained facility without the benefit of a star at the correct distance, I imagine that the majority of our food will be grown using grow lights. Currently, there are lights that have a wide color spectrum which is vital for indoor plant growth.
What about growing mediums?
Hell we can grow green beans in an old boot with some dirt here on Earth but what will we use in space?
Soil is heavy so an aeroponic system might be the most efficient system but some plants have to have soil and will not thrive in any type of hydroponics. Their root structures are too fragile or complex to survive without a sub straight. If we want to have fish of any kind aquaponics might be a good solution.
I imagine variety might be an issue but then again, with enough space and ingenuity, seed wouldn’t be a huge problem. Between the seed vault in Norway, the National Center for Genetic Resources Preservation and the thirteen other seed vaults I think we might have a decent chance of bio diversity.
Now if we can manage to build ships like the one with an ocean in it or one with a whole forest growing in it then we are talking a whole new ballpark. We could create an entire biome that housed not only humans but animals as well.
However, I would think that after a long time in space on a generation ship people would probably have evolved away from the current state of being omnivorous. Cryo-chamber people… I would guess still crave bacon to a large degree… unless the need to eat meat had been eliminated prior to travel. In which case I would wonder how and if humanity evolved to a point where they did not consume meat.
Back to the food forest. Insects would play a large role in the fertility of said forest unless you had an army of people to hand pollinate the biome. Personally, I would love to pack a hive of bees, a legion of grasshoppers, an army of caterpillars and a kaleidoscope of butterflies in the ship.
Honestly we will have to look at food production and consumption from a wholistic perspective.