Ignore the front of the bag. The numbers that decide whether a food is good sit in three places: the guaranteed analysis, the ingredient list, and the calorie statement. Everything else — the photographs of salmon, the word "holistic", the gold medal — is unregulated decoration. Read those three blocks, convert protein and fat to a dry-matter basis, and most premium claims collapse inside a minute.
Start with water, because water changes everything
Guaranteed analysis lists crude protein, fat, fibre, moisture and ash as percentages of the product exactly as it sits in the can, water included. That is why canned food always looks weaker than kibble and almost never is. Do the arithmetic once and the confusion disappears.
| Product | Protein as fed | Moisture | Protein dry matter |
|---|---|---|---|
| Dry food | 34% | 10% | 37.8% (34 ÷ 90) |
| Pâté can | 11% | 78% | 50.0% (11 ÷ 22) |
| Gravy pouch | 8% | 85% | 53.3% (8 ÷ 15) |
The formula is protein ÷ (100 − moisture) × 100. Run it on fat too: 5% fat in a 78%-moisture pâté is 22.7% fat dry matter, which is why "low fat" cans are rarely low fat.
The carbohydrate number nobody prints
Carbohydrate is almost never declared, because it is not a required guarantee. You get it by subtraction: 100 minus protein, minus fat, minus fibre, minus moisture, minus ash (the mineral residue). A kibble at 34% protein, 18% fat, 3% fibre, 10% moisture and 7% ash leaves 28% carbohydrate as fed, or 31% on a dry-matter basis. For a diabetic cat, 31% is the number that decides the food.
Ingredient splitting: how meat slides down the list
Ingredients are listed by weight before cooking. That single rule creates the most common trick in the industry. "Chicken, chicken meal, brown rice, ground corn, corn gluten meal, rice bran, brewers rice" looks like chicken first. But brown rice plus ground corn plus rice bran plus brewers rice is four rice-and-corn entries, and together they outweigh the chicken. Split one ingredient into its fractions and it drops below the meat on the printed list while remaining the largest thing in the bag.
The counter-move is to add up the fractions. If the combined rice, corn, pea and potato entries outweigh the combined meat entries, the food is plant-heavy no matter what the first word says. Fresh meat makes this worse: chicken is 70% water, so 10 kg of it delivers about 3 kg of dry matter — the same as 3 kg of chicken meal, at a higher list position for less protein.
What the words on the front are allowed to mean
- "With chicken" — the named ingredient makes up at least 3% of the product.
- "Chicken dinner", "chicken entrée", "chicken formula" — at least 25%.
- "All chicken" or "100% chicken" — at least 95%, water used in processing excluded.
- "Grain-free" — no grain. Says nothing about carbohydrate, which often comes from peas, tapioca or potato.
- "Natural", "holistic", "premium", "human-grade" — no enforced definition in most markets. "Human-grade" only means something if the plant itself is licensed for human food production.
The adequacy statement tells you if it is a meal at all
Somewhere in small print is one of three sentences, and this is the single most important line on the package. "Formulated to meet the nutritional levels established by the AAFCO Cat Food Nutrient Profiles for maintenance" means the recipe was calculated, not tested. "Animal feeding tests using AAFCO procedures substantiate that this product provides complete and balanced nutrition" means cats ate it and stayed healthy over a defined trial. Both are legal.
The third sentence, "for intermittent or supplemental feeding only", means the product is not complete. Treats, toppers, milk replacers and many "complementary" pouches carry it. If that phrase is on the only food your cat eats, the cat is on a deficient diet.
Also check the life stage. "Adult maintenance" is not adequate for a kitten under one year, and "all life stages" is the phrase that covers growth.
Calories per kilogram, not per cup
Dry food runs 3,500–4,300 kcal per kilogram; canned food 70–110 kcal per 100 g; pouches 60–90 kcal per 100 g. Cups are useless as a unit because kibble density varies by a factor of two between brands. A 4 kg indoor neutered cat needs roughly 240 kcal a day, which is about 60 g of a 4,000 kcal/kg kibble or two 85 g cans of a 75 kcal/100 g pâté.
Divide the price by the calories. A 2 kg bag at 4,000 kcal/kg holds 8,000 kcal; at $18 that is $0.23 per 100 kcal. A 24-can case of 85 g pâté at 75 kcal/100 g holds 1,530 kcal; at $54 that is $3.53 per 100 kcal — a 15-fold gap.
The five numbers to compare before you buy
| Figure | Target, adult cat | Why |
|---|---|---|
| Protein, dry matter | 40–50% | Muscle maintenance; 26% is the legal floor |
| Fat, dry matter | 15–22% | Energy density and palatability |
| Carbohydrate, dry matter | Under 10% preferred | No dietary requirement for carbohydrate |
| Phosphorus, dry matter | 0.5–0.8% | Under 0.5% if kidney disease is present |
| Calcium : phosphorus | 1.1–1.3 : 1 | Outside this range, bone and kidney risk |
Add taurine: it should appear by name at 0.1% dry matter or more, and most reputable foods declare 0.15–0.25%.
Where labels mislead even when they are accurate
"Vet recommended" is a marketing survey, not a clinical endorsement. "Indoor" and "senior" have no legal nutrient definition. The real red flags are narrower: no adequacy statement, no calorie figure, no named animal protein in the first three ingredients, and a guaranteed analysis with a minimum protein but no maximum ash.
One free check before committing to a 5 kg bag: the brand's recall history. One recall is not disqualifying; three in four years on the same line is. Compare the shortlist against our food guides, then use the food calculator to turn kcal/kg into grams per day for your cat's weight.
Frequently asked
Is higher protein always better in cat food?
No. 40–50% dry matter suits most healthy adults, but a cat with advanced kidney disease may need 26–30%, and a cat with a diagnosed liver shunt needs careful formulation. Higher is better than the 26% legal minimum only when the protein is animal-based and the cat's kidneys are healthy.
Does grain-free mean low carbohydrate?
No. Grain-free foods frequently replace grain with peas, lentils, tapioca or potato, and total carbohydrate often lands at 25–40% dry matter. Check the guaranteed analysis by subtraction rather than trusting the front of the bag.
What if the label has no calorie statement?
Ask the manufacturer for kcal/kg in writing. In many jurisdictions it is voluntary on packaging, but it is required in the product guide. Without it you cannot portion accurately, and a food whose maker will not supply a number is a poor choice for a cat you are trying to keep at a stable weight.