Why do I stop eating corpses? Should I keep eating them anyway?
You stop eating the {monster} corpse occurs when something in your environment changes that the game thinks might effect your desire to continue eating. It happens when a new monster enters your line of sight, and if you are attacked.
It can also happen if you choke, choose to stop eating due to fullness, or if something happens to the object you're eating (for example, a troll reviving while you're blind, so that the line-of-sight condition doesn't apply, or if the food decays away during your meal. 1)
I believe that vomiting interrupts eating as well, but I'm not entirely positive about that one.