I don’t ever state this explicitly in Bury’em Deep, but food for spacers is more complicated than simple nutrients. In fact, what is called nutrient paste is a complex concoction which requires advanced biochemical and medical engineering facilities to produce. This advanced technological base is necessary to create the drugs present in all official nutrient paste, the same drugs which permit healthy long term human body development and functioning in prolonged exposure to null-gee and high radiation environments. These drugs were foundational to the expansion of humanity beyond the gravity well of Earth and the carefully maintained full-gee habitats, and the most straightforward way their designers found to distribute them was through the nutrient paste that every spacer needed to eat.
This reliance on drugs for prolonged health in null-gee, coupled with the extensive industrial technology-based required to produce those drugs, effectively resulted in hydraulic empire for all spacers who strayed from full-gee habitats for any period of time. Spacers who left their full-gee habitats for short periods would generally experience the same health troubles that current-day astronauts do; but with humanity’s expansion deeper into the solar system and the longer travel times involved, extended stays outside full-gee became commonplace. With these drugs, spacers could survive and even thrive in null-gee with no ill effects (beyond the predictable changes to children’s body shape which came with growing up in null-gee). Without these drugs, humans of all ages eventually developed a series of health complications which was first called “space scurvy” (and which was eventually simply referred to by spacers as “scurvy”).
Any station or group of spacers which did not have a sufficient tech base to produce their own drugged nutrient paste had to remain relatively close to a full-gee habitat or otherwise depend on a station that *did* produce its own drugged nutrient paste. At the time of Bury’em Deep, most nutrient paste is assumed to contain the requisite drugs—any that does not is deemed deficient. Stations which wish to exert control over dependent populations can sometimes simply refuse to provide the necessary nutrient paste. Even though the dependent population may be able to produce the food that they need to survive, their quality of life dramatically decreases. Relatedly, pirates and outlaws who have been prevented from accessing official nutrient paste are often disease-ridden and suffer from scurvy.
The cocktail of drugs in nutrient paste has advanced multiple times, usually delivering additional health benefits with each new generation (and sometimes producing terrible side effects in some portion of the population). New generations of paste are publicly hailed as an improvement, and different stations and polities may have their own official brands of nutrient paste, or may license the rights to produce specific brands of medicated nutrient paste from rights-holders. Some developers offer their recipes for free to paste-production complexes, while others charge an arm and a leg (sometimes with the promise that their particular strain of nutrient paste will offer further health benefits or a specific underlying flavor profile and mouth-feel prior to use of standard flavor additives or texture alterations). Only paste-production complexes with broad public funding have been known to offer nutrient paste for free, and the most common form of generosity is to provide nutrient paste at-cost.