Our Verdict
When comparing egg whites to whole eggs, we picked the whole eggs.
Why?
Egg whites are mostly protein. Egg yolks are mostly fat, with some protein.
However, fat ≠ bad, and the yolk is also where the choline is stored, which itself (as well as its benefits for your brain) will tend to reduce fat storage in the body.
Furthermore, the yolk contains an assortment of vitamins, minerals, and essential amino acids. After all, the yolk is there specifically to contain everything needed to turn a cluster of cells into a small bird.