Contains possibly the single most self-aware line for a series about US military personnel.

the only time eating did sthg iirc was when she gained resistance to the rot status effect by eating strange maggots that caused it, but to be fair, that was instrumental in her getting some of her most powerful abilities (you can't use rot unless you have high resistance to it because it backfires)

spider isekai girl got xp to grow more powerful directly from killing monsters (or humans), not from eating them, but she developed a personal philosophy of eating them to show them respect

glasslip from the ancient scriptures... the only thing I remember about that show is that there were chickens and that the OP was good