Lexx is an organic spacecraft. I can't work out what it eats for its everyday sustenance. Is it garbage, humans, animal life, vegetables? Is it simply an omnivore that can eat any organic matter or perhaps eat even inorganic stuff.
The one thing I am sure of is that Lexx can re-eat moths that it has spawned.
The Moth Breeding chamber is located somewhere below the bridge, it is where the moths used to explore planet's surfaces are bred. Moth breeders themselves are supposedly created and maintained within the Lexx as well. https://lexx.fandom.com/wiki/The_Lexx
I can't find the reference to Lexx eating moths but I'm pretty sure it happened in times of hunger.
Research
I have found the following references but I'm still not clear about how the huge Lexx space-vessel maintained its energy from day to day when not destroying planets.
Lexx and the crew are running out of food resources. Desperate they visit what appears to be a garbage planet, but quickly become separated and under go a series of individual adventures in a culture that's basically cannibalistic. https://www.imdb.com/title/tt0119043/
Looking for protoblood, the Lexx returns to the Cluster to learn that a huge insect survived. This insect had controlled The Divine Order and His Divine Shadow in order to eat all human inhabitants of the 20,000 planets. https://en.wikipedia.org/wiki/Lexx
The Galley is where the crew goes to eat (sans Kai and, of course, 790). The goop that the Lexx produced was yellow-orange in color, but later it was green, and then blue. The Lexx might produce different looking and tasting goop depending on what he has eaten himself. Stan constantly orders delicious and exotic foods despite always getting a container filled with goop. https://lexx.fandom.com/wiki/The_Lexx