Need a good bean counter, but don't let him decide what restaurant to eat at.
Okay the thing about space marines is like. they are huge mammals, practically bear sized, active primates. On top of the normal caloric needs for a large animal to be active and fast for so long, their bodies are constantly bioactive- they produce corrosive salive, they're conatantly healing from horrible wounds- those proteins are expensive and that mass has to come from somewhere. And don't fucking "oh genetic engineering they're so perfect" me, you can only be SO bioeffecient, these are still modified humans, presumably you're not recreating their biomolecular structure.
They have to eat a TON right? They probably have the caloric and vitamin demands of a pregnant tiger, and there's hundreds of them on these ships. Are there spaceship cows tgey're slaughtering? Do they just guzzle gallons of reconstituted protein paste?
And I think this caloric need, if emphasized, only helps accentuate the fact that a Space Marine is only as good as his supplies, as the labor done by the citizen-slaves of the Imperium- whether their work is tithed to loyalists or raided by traitors. And the inequality is the point, the irony that these superhuman gods NEED the work of hundreds of human laborers to survive- that's so important! That's the evil of the imperium, the hypocracy of power!
Space Marines should be ravenous little fuckers. Show them eating more.