Beneful Original ingredients:
Ground yellow corn, chicken by-product meal, corn gluten meal, whole wheat flour, beef tallow preserved with mixed-tocopherols (source of Vitamin E), rice flour, beef, soy flour, sugar, sorbitol, tricalcium phosphate, water, animal digest, salt, phosphoric acid, potassium chloride, dicalcium phosphate, sorbic acid (a preservative), L-Lysine monohydrochloride, dried peas, dried carrots, calcium carbonate, calcium propionate (a preservative), choline chloride, vitamin supplements (E, A, B-12, D-3), added color (Yellow 5, Red 40, Yellow 6, Blue 2), DL-Methionine, zinc sulfate, glyceryl monostearate, ferrous sulfate, niacin, manganese sulfate, calcium pantothenate, riboflavin supplement, biotin, thiamine mononitrate, garlic oil, copper sulfate, pyridoxine hydrochloride, folic acid, menadione sodium bisulfite complex (source of Vitamin K activity), calcium iodate, sodium selenite.
F-4090

Purina One Lamb & Rice ingredients:

Lamb, brewers rice, oat meal, corn gluten meal, poultry by-product meal (natural source of glucosamine), whole grain corn, animal fat preserved with mixed-tocopherols (form of Vitamin E), chicken cartilage (natural source of glucosamine), calcium carbonate, dicalcium phosphate, animal digest, potassium chloride, malted barley flour, salt, L-Lysine monohydrochloride, choline chloride, brewers dried yeast, zinc sulfate, Vitamin E supplement, ferrous sulfate, manganese sulfate, niacin, Vitamin A supplement, calcium pantothenate, thiamine mononitrate, copper sulfate, riboflavin supplement, Vitamin B-12 supplement, pyridoxine hydrochloride, garlic oil, folic acid, Vitamin D-3 supplement, calcium iodate, biotin, menadione sodium bisulfite complex (source of Vitamin K activity), sodium selenite.
L-4162


Purina One Beef & Rice ingredients:

Lamb, brewers rice, oat meal, corn gluten meal, poultry by-product meal (natural source of glucosamine), whole grain corn, animal fat preserved with mixed-tocopherols (form of Vitamin E), chicken cartilage (natural source of glucosamine), calcium carbonate, dicalcium phosphate, animal digest, potassium chloride, malted barley flour, salt, L-Lysine monohydrochloride, choline chloride, brewers dried yeast, zinc sulfate, Vitamin E supplement, ferrous sulfate, manganese sulfate, niacin, Vitamin A supplement, calcium pantothenate, thiamine mononitrate, copper sulfate, riboflavin supplement, Vitamin B-12 supplement, pyridoxine hydrochloride, garlic oil, folic acid, Vitamin D-3 supplement, calcium iodate, biotin, menadione sodium bisulfite complex (source of Vitamin K activity), sodium selenite.
L-4162


As you can see the main ingredient in Beneful is corn, a filler. And look how high up sugar is listed in the ingredients!

(Ingredients are listed 1st to last, high to low. In other words the higher on the list it is, the more of it there is in the food - the lower on the list, the less there is.)