I've been thinking a lot lately about how Kabru deprives himself.
Kabru as a character is intertwined with the idea that sometimes we have to sacrifice the needs of the few for the good of the many. He ultimately subverts this first by sabotaging the Canaries and then by letting Laios go, but in practice he's already been living a life of self-sacrifice.
Saving people, and learning the secrets of the dungeons to seal them, are what's important. Not his own comforts. Not his own desires. He forces them down until he doesn't know they're there, until one of them has to come spilling out during the confession in chapter 76.
Specifically, I think it's very significant, in a story about food and all that it entails, that Kabru is rarely shown eating. He's the deuteragonist of Dungeon Meshi, the cooking manga, but while meals are the anchoring points of Laios's journey, given loving focus, for Kabru, they're ... not.
I'm sure he eats during dungeon expeditions, in the routine way that adventurers must when they sit down to camp. But on the surface, you get the idea that Kabru spends most of his time doing his self-assigned dungeon-related tasks: meeting with people, studying them, putting together that evidence board, researching the dungeon, god knows what else. Feeding himself is secondary.
He's introduced during a meal, eating at a restaurant, just to set up the contrast between his party and Laios's. And it's the last normal meal we see him eating until the communal ending feast (if you consider Falin's dragon parts normal).
Kabru's response here is such a non-answer, it strongly implies to me that he wasn't thinking about it until Rin brought it up. That he might not even be feeling the hunger signals that he logically knew he should.
They sit down to eat, but Kabru is never drawn reaching for food or eating it like the rest of his party. He only drinks.
It's possible this means nothing, that we can just assume he's putting food in his mouth off-panel, but again, this entire manga is about food. Cooking it, eating it, appreciating it, taking pleasure in it, grounding yourself in the necessary routine of it and affirming your right to live by consuming it. It's given such a huge focus.
We don't see him eat again until the harpy egg.
What a significant question for the protagonist to ask his foil in this story about eating! Aren't you hungry? Aren't you, Kabru?
He was revived only minutes ago after a violent encounter. And then he chokes down food that causes him further harm by triggering him, all because he's so determined to stay in Laios's good graces.
In his flashback, we see Milsiril trying to spoon-feed young Kabru cake that we know he doesn't like. He doesn't want to eat: he wants to be training.
Then with Mithrun, we see him eating the least-monstery monster food he can get his hands on, for the sake of survival- walking mushroom, barometz, an egg. The barometz is his first chance to make something like an a real meal, and he actually seems excited about it because he wants to replicate a lamb dish his mother used to make him!
...but he doesn't get to enjoy it like he wanted to.
Then, when all the Canaries are eating field rations ... Kabru still isn't shown eating. He's only shown giving food to Mithrun.
And of course the next time he eats is the bavarois, which for his sake is at least plant based ... but he still has to use a coping mechanism to get through it.
I don't think Kabru does this all on purpose. I think Kui does this all on purpose. Kabru's Post Traumatic Stress Disorder should be understood as informing his character just as much as Laios's autism informs his. It's another way that Kabru and Laios act as foils: where Laios takes pleasure in meals and approaches food with the excitement of discovery, Kabru's experiences with eating are tainted by his trauma. Laios indulges; Kabru denies himself. Laios is shown enjoying food, Kabru is shown struggling with it.
And I can very easily imagine a reason why Kabru might have a subconscious aversion towards eating.
Meals are the privilege of the living.
