Dog Food Analysis grades the food according to the highest protein. I feed Natural Balance Sweet Potato & Venison which has 20% crude protein. I used to feed Evo Red Meats which has a high protein of 42%. Just because a food has lower protein doesn't mean it's a lower quality food. I chose (well, it's more like they chose
)to go w/NB because it's grain free & has lower protein. As some have stated, some Yorkies do not do well on a high protein diet.