One sentence on the back of a cat food bag decides whether the food is a complete diet or a snack: the AAFCO nutritional adequacy statement. It comes in 4 forms, and only 2 of them can say complete and balanced. The other 2 mean the food is a topper, a treat, or unproven. Read that sentence before you read the protein percentage, because 32 percent protein means nothing if the food is labeled for intermittent feeding only.
The 4 statements, and what each one proves
AAFCO is a group of state feed regulators, not a testing lab. A manufacturer either calculates a formula against the AAFCO Cat Food Nutrient Profiles, runs a feeding trial, or makes no claim at all. The 4 versions you will see on US bags, plus the imported bags that copy them, look like this.
| Statement | Method behind it | Cats tested | Weeks of trial |
|---|---|---|---|
| Formulated to meet the AAFCO Cat Food Nutrient Profiles | laboratory calculation on paper | 0 | 0 |
| Animal feeding tests using AAFCO procedures substantiate | controlled feeding trial | 8 minimum | 26 |
| Intended for intermittent or supplemental feeding only | no adequacy claim | 0 | 0 |
| No AAFCO statement printed | no adequacy claim | 0 | 0 |
Type 1: formulated to meet the profiles
This is math, not cats. The manufacturer sends the recipe to a lab, measures each nutrient, and checks it against the profile for the stated life stage. It is legal, common, and cheap: no 8-cat colony and no 26-week feeding period. Its weakness is that a formula can hit every minimum and still be poorly digested, so a food can pass on paper and produce loose stool in your kitchen. Roughly speaking, most supermarket and many mid-range brands use this route.
Type 2: feeding trials, the harder test
The wording is animal feeding tests using AAFCO procedures substantiate that the product provides complete and balanced nutrition. For adult maintenance the protocol runs at least 26 weeks with a minimum of 8 cats, with weight, intake, bloodwork, and general health tracked. Growth and reproduction protocols use kittens and breeding queens and run shorter. Fewer brands pay for this, which is why the trial wording is far less common on the shelf.
Neither method guarantees your cat will eat the food, and neither tests palatability. A trial proves adequacy, not preference.
Type 3: intermittent or supplemental feeding only
This sentence means the product is not a complete diet. Toppers, broths, milk replacers for weaning, and many prescription-style treats carry it. Fed as 10 to 20 percent of daily calories, that is fine. Fed as the whole diet for 3 months, it can produce deficiencies in taurine, calcium, or vitamin E, and the damage shows up in bloodwork long before it shows up in the coat.
Type 4: no statement at all
Treats, dental chews, and some imported bags have no AAFCO statement anywhere. Absence is not a loophole in the law; it means the product makes no nutritional adequacy claim, so you cannot assume it is complete. A bag with 6 marketing badges and no adequacy sentence is a treat, whatever the front panel says.
Life stage: 4 legal words and 1 that is not
The statement must name a life stage, and only 4 count: growth (kittens), gestation and lactation (pregnant or nursing queens), adult maintenance, and all life stages. All life stages is the strictest, because the food must meet the growth profile plus the adult one. Senior is not an AAFCO life stage; a bag labeled senior is still either adult maintenance or all life stages, so check which. Kitten food labeled adult maintenance is a real labeling error to look for on cheap imports.
The minimums behind the words
| Nutrient (% dry matter) | Adult maintenance | Growth |
|---|---|---|
| Crude protein | 26% | 30% |
| Crude fat | 9% | 9% |
| Calcium | 0.6% | 1.0% |
| Phosphorus | 0.5% | 0.8% |
| Taurine (extruded) | 0.10% | 0.20% |
| Calcium to phosphorus ratio | 1:1 to 2:1 | 1:1 to 2:1 |
Those are floors, not targets. A food at exactly 26 percent protein and 0.10 percent taurine meets the profile and has no margin, which matters for a cat with kidney disease or heart disease; ask your vet where the margin should be for your cat.
Trap 1: the translated sticker on the import
Imported bags often carry a pasted local-language label added by the importer, and that label is where accuracy dies. It may drop the AAFCO sentence entirely, or translate intermittent or supplemental feeding only as complete food. Photograph the original printed panel before the sticker goes on, and compare the life stage word on both. If the sticker and the bag disagree, the bag wins.
Trap 2: as-fed percentages versus dry matter
Guaranteed analysis numbers are as-fed, moisture included. A canned food at 78 percent moisture and 11 percent protein is 50 percent protein on a dry matter basis; a dry food at 10 percent moisture and 32 percent protein is 35.6 percent dry matter protein. The can looks weaker and is stronger. Convert before you compare: divide the nutrient percentage by (100 minus moisture percentage), then multiply by 100.
Trap 3: units and the calorie line
Energy is printed as kcal/kg, kcal/cup, or kcal/can, and the 3 are not interchangeable. A dry food at 3,800 kcal/kg and 110 g per cup works out to 418 kcal/cup; a pate at 1,050 kcal/kg and 85 g per can is 89 kcal/can. A 4.5 kg cat needs roughly 200 to 250 kcal a day, so 1 can plus 100 g of dry is already at the ceiling. Protein, fat, and carbohydrate supply about 3.5, 8.5, and 3.5 kcal per gram.
6 checks in the aisle, 30 seconds
- Find the adequacy sentence on the back or side panel, not the front.
- Confirm it names 1 of the 4 life stages.
- Confirm the method: formulated or feeding trial.
- If it says supplemental only, buy it as a topper for 10 to 20 percent of calories.
- Note moisture, then convert protein and fat to dry matter.
- Check kcal/kg and the gram weight of a cup or can before you compare price per day.
Label reading pairs with 3 other pages: the ingredient-panel walkthrough, the moisture and calorie comparison, and the toxic food and plant list for anything a cat eats by accident.
Terms mentioned in this article
Frequently asked
Is a feeding trial better than a formulated food?
A feeding trial is stronger evidence because 8 or more cats actually ate the food for 26 weeks and their weight and bloodwork were tracked, while a formulated food is a lab calculation against a nutrient table. That does not make every trial food better for your cat: digestibility, calorie density, and your cat's own tolerances still decide. Treat the trial statement as a tiebreaker, not a ranking.
Why does senior not count as an AAFCO life stage?
AAFCO recognizes only 4 life stages: growth, gestation and lactation, adult maintenance, and all life stages. Senior is a marketing category, so a senior bag still carries an adult maintenance or all life stages statement. That matters because a 12-year-old cat with kidney disease may need a different phosphorus level than the adult minimum of 0.5 percent, and the senior label tells you nothing about that.
How do I compare a can and a bag fairly?
Convert both to dry matter and to calories per day. Divide each nutrient percentage by 100 minus the moisture percentage, then multiply by 100. Then price the food per 100 kcal rather than per kilogram: a 3,800 kcal/kg dry food and a 1,050 kcal/kg pate differ by more than 3 times, so the cheaper bag per kilo can cost more per day.