Yeah, this is Science Diet Indoor cat formula's main ingredients:
"Chicken By-Product Meal, Corn Gluten Meal, Brewers Rice, Whole Grain Corn, Animal Fat, Powdered Cellulose, Chicken Liver Flavor, Lactic Acid, Soybean Oil, Soybean Mill Run, Potassium Chloride, Choline Chloride, Calcium Sulfate, Calcium Carbonate, Iodized Salt"
Instead of chicken meal, its byproduct as a primary source. Secondary is less expensive corn gluten instead of a meat protein. Third is not just rice, but brewers rice (aka no nutrient byproduct rice), corn which is not only high carb but a common allergen for many cats, not chicken liver but just flavor... bah!
So 40% of the calories are from carbs which is high, and it has almost no fat, also bad.