A pellet food contains as good a mix of diet as possible, it is not just meat...I.e. Macdonalds is just low grade beef, bread and some chips but a pellet food aims to provide a balanced diet....more like a Sunday roast with all of the veg included along with your days supply of vitamins.
Having said this I think pellet is a good basis which can be supplemented with many fresh foods. Even Macdonalds can become part of a balanced diet.
I am trying to live on wine alone but the scurvy is a pain!