ColonelKappe wrote:I'm a bit of a Halo freak so I may be able help with this. They were strict predators, however, while many theories have arose, by what methods they naturally ate is unknown. However, if you ever read some of the Halo books (Particularly Halo: Ghosts of Onyx, my personal favourite book), it is revealed that Elites simply "eat" via a tube that dispenses a strange paste, which is present on all Covenant vessels, and provides Elites with all the nutrition they need quickly and efficiently. A task well within the Covenant's technology level.
If you don't want to go through the hassle of reading the books, http://halo.wikia.com/wiki/Sangheili is an exceptional site with tons of interesting information.
So they cannibalize for the sake of eating an actually tasty meal. Makes perfect sense.