Purina One 3

My Pit Bull Lola has been on Purina One for about 3 months. She eats it and there are no problems. If I feed her some treats or something other than Purina One she will choose not to eat her dinner/breakfast. I don't know if she does not like the taste of Purina One or what. I have looked at the ingredients of Purina One and they look very bad because of corn meal, and chicken and meat by-products. By-producs are leftover chicken and cow feet, liver, heart, stool, bones toenails. fingernails, ect.