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What's actually in Purina ONE?
We analyzed Purina ONE Tender Selects Blend Chicken, one of their most popular cat formulas. The first five ingredients are chicken, corn gluten meal, soybean meal, brewers rice, and wheat flour. Poultry by-product meal, beef fat preserved with mixed tocopherols, animal digest, whole grain corn, and soy protein isolate fill out the top ten.
Chicken as the first ingredient is the one genuine bright spot. But the next four ingredients paint a clear picture of cost optimization. Corn gluten meal at number two is a cheap plant protein booster — cats are obligate carnivores and have no nutritional need for corn protein. Soybean meal at three is another plant protein filler. Brewers rice at four is a low-quality rice fragment. Wheat flour at five adds yet another grain. Then whole grain corn appears at nine and soy protein isolate at ten — meaning corn shows up twice and soy shows up twice. When you count the plant-based protein sources (corn gluten meal, soybean meal, soy protein isolate) and the grain fillers (brewers rice, wheat flour, whole grain corn), the formula is overwhelmingly plant-based despite leading with chicken. Shop on Amazon →
The good stuff
Chicken at number one is a named, real animal protein — which still puts it ahead of the true bottom tier where unnamed meat meals or grains lead. Fish meal at position eleven provides some animal-sourced protein and a small amount of omega-3s. Beef fat preserved with mixed tocopherols means natural preservation rather than artificial BHA/BHT. Taurine supplementation is present and essential for cats.
The price is genuinely low. Purina ONE is one of the most affordable cat foods that still starts with a named chicken ingredient, and for owners on a strict budget, the basics are covered — AAFCO complete and balanced nutrition is met.
The not-so-good stuff
The protein inflation is the central problem. The guaranteed analysis might show a respectable protein percentage, but with corn gluten meal at two, soybean meal at three, and soy protein isolate at ten, a large portion of that protein comes from plant sources that don't provide the amino acid profile cats need. Cats require animal-based proteins for essential amino acids like taurine, arachidonic acid, and certain forms of vitamin A that plant proteins simply can't deliver in the same way.
Caramel color is an unnecessary cosmetic additive that serves zero nutritional purpose — it's there to make the kibble look a certain way to human buyers. Cats don't care what color their food is. It's a small thing, but it signals a formula designed to appeal to shoppers rather than nourish cats.
Animal digest is a vague palatability enhancer made by chemically or enzymatically breaking down animal tissues. "Animal" without specifying which animal is as non-specific as it gets. No probiotics, no fruits or vegetables, no antioxidant-rich ingredients. The formula is stripped down to the minimum.
How it compares
Purina ONE Cat at C/58 is the lowest-scoring Purina cat food and drops into D territory — below Purina Pro Plan (C/56), which at least avoids caramel color and includes dried egg product. It also falls below Iams (C/62), which includes FOS prebiotics and L-Carnitine, and Hill's Science Diet (C/60), which includes fish oil. All of those cost somewhat more, but they earn their C grades with at least some functional additions.
The gap to better food is wide. Blue Buffalo (B/76) and Taste of the Wild (B/76) score 24 points higher with genuinely meat-forward formulas, named protein sources throughout, and none of the vague "animal" ingredients. Wellness (B/80) leads the category. The jump from D to B is the difference between a formula built around cost and one built around nutrition.
Read the full breakdowns in our head-to-head comparisons: Iams vs Purina ONE and Purina ONE vs Royal Canin.
The bottom line
Purina ONE Tender Selects Blend earns a C grade (58/100) from KibbleIQ. Chicken as the first ingredient, added soy protein concentrate for amino-acid completeness, dried chicory root as a prebiotic, and the replacement of "animal digest" with named natural flavor are all real improvements over the prior formulation. The reliance on corn gluten meal, wheat flour, and the still-present caramel color keep it in C territory rather than B. If budget is your primary constraint, Purina ONE is now a defensible mid-pack choice that meets AAFCO and matches Royal Canin (C/58) on score at roughly half the price. If you can stretch a few dollars per bag, B-tier brands like Blue Buffalo Indoor (B/78) deliver meaningfully better ingredients for cats' obligate-carnivore needs. Shop on Amazon →