Methodology

Cats are obligate carnivores. Unlike dogs or humans, they have hard biological requirements for nutrients found only in animal tissue (including taurine, arginine, and arachidonic acid) that they cannot synthesize in sufficient amounts from plant sources. Taurine deficiency alone can cause dilated cardiomyopathy and retinal degeneration.

Human food-rating systems like Nutri-Score were built for human diets: they reward fiber, penalize fat, and measure against human nutrient reference values. Those judgments are simply wrong for cats. A high-fat, low-carbohydrate, animal-protein-dominant food is exactly what a healthy adult cat needs. We built the CFC Score from scratch, grounded in AAFCO feline nutrient profiles, FDA guidance, EFSA opinions, and published veterinary research.

A single number from 0 to 100, grouped into four color bands. It blends three pillars, each weighted by how much it affects a cat's long-term health.

Scored on a dry-matter basis where data allows. Sub-factors:

• Animal-protein dominance. Is a named animal protein (chicken, salmon, turkey) the first ingredient? Plant proteins like pea protein, corn gluten meal, and soy protein isolate inflate the crude-protein figure but have lower biological value for cats, so they are discounted.
• Essential nutrient sufficiency. Crude protein, taurine, arginine, arachidonic acid, crude fat, and key vitamins and minerals checked against the AAFCO feline nutrient profile for the stated life stage. Taurine is weighted heavily; deficiency is directly linked to dilated cardiomyopathy and retinal degeneration.
• Carbohydrate and filler load. Lower is better. Heavy grain or starch fillers (corn, wheat gluten, potato starch) reduce the score.
• Moisture. Wet and canned formats receive a small bonus for supporting hydration and urinary-tract health, which is clinically significant in cats.
• AAFCO life-stage adequacy. Complete and balanced for a defined life stage is required to score well. Products substantiated by feeding trials score higher than those substantiated by formulation alone.

Each additive is matched against our knowledge base and assigned a risk tier based on recommendations from the FDA, EFSA, and the WHO/IARC, plus published veterinary studies. Every flagged additive on a product page shows its function, tier, a plain-language health impact, and the source.

• Named versus unnamed protein and fat sources. Chicken is named; "poultry" is not.
• Manufacturer transparency: sourcing disclosure, country of origin, who formulates the food.
• FDA recall history for the brand or product line.

We use this pillar instead of an organic bonus because organic certification has far less impact on feline health than protein quality, transparency, and additive load.

Some findings override the weighted formula entirely:

• Propylene glycol detected: automatic Bad band. The product is capped in the 0–24 range regardless of nutritional quality, because propylene glycol is FDA-prohibited in cat food.
• Any Tier 3 additive present: maximum possible score is 49 (top of the Poor band), regardless of nutrition.
• Not complete and balanced: if a product is not AAFCO complete and balanced for any life stage and is not labeled a treat or complementary food, a warning banner appears on the product page.

Every pillar is computed from the text of an ingredient list and a guaranteed analysis panel, as recorded in a community database. That puts real limits on what a score can honestly claim, and we would rather state them than let a number imply otherwise.

• Label language. The additive and transparency checks work by matching known terms. They cover English, French, German, Spanish, Italian and Dutch. On a label in any other language the checks match nothing, and nothing matched is not the same as nothing wrong. Where that happens the product page says the list could not be read, withholds the “no flagged additives” finding, and marks the score low-confidence. It never reports an unreadable label as clean.
• Missing data. Most records are incomplete. A pillar that cannot be computed is left out and its weight redistributed, rather than scored as zero; where too little is known, no score is shown at all.
• Transcription errors. Figures are entered by volunteers. Values outside a plausible range for cat food are discarded rather than scored.
• What a label omits. Ingredient sourcing, manufacturing standards, recall history and batch testing are not on the panel, so they are not in the score.

• AAFCO: model regulations and feline nutrient profiles
• FDA Center for Veterinary Medicine: pet food rules, prohibited ingredients, recall records
• EFSA: European Food Safety Authority opinions on additives
• Open Pet Food Facts: open product catalog (barcode lookup and ingredient data)
• Published peer-reviewed literature, cited per additive on each product page.