Feline Nutrition: Protein, Fat and Calories
Cats are obligate carnivores. Protein and fat requirements, taurine, energy needs and how feline nutrition drives the daily portion in your cat's bowl.
What Do Cats Need From Their Food?
A cat is an obligate carnivore, an animal that requires nutrients found only in animal tissue and cannot thrive on plant-based or dog-formulated diets. Cats require taurine, arachidonic acid and preformed vitamin A, and they cannot synthesize these from the plant precursors that dogs convert readily. This is the single fact that separates feline nutrition from every other companion-animal diet.
Four requirements define a good cat food: high animal protein, moderate fat, minimal carbohydrate and plenty of water, all matched to energy needs by life stage. AAFCO adult minimums are 26% protein and 9% fat on a dry-matter basis, rising to 30% protein for growth and reproduction. Because dog food is built to lower protein and lacks guaranteed taurine, it is deficient for cats no matter how premium the brand.
Those numbers come from named authorities rather than marketing. AAFCO nutrient profiles, NRC requirements and WSAVA selection guidance set the feline standard, and the rest of this page defines the vocabulary every other cat-feeding decision borrows. If you already know the framework, you can jump straight to homemade cat food safety basics, which depends on getting these requirements exactly right.
- Obligate carnivore: derives essential nutrients only from animal tissue.
- High protein: ≥26% DM adult, ≥30% DM kitten (AAFCO minimums; many healthy diets run 35-50%).
- Moderate fat: ≥9% DM, the densest energy source and the carrier of arachidonic acid.
- Minimal carbohydrate and high moisture: matching the water content of natural prey.
Protein: Why Cats Need Far More Than Dogs
Cats require roughly twice the protein of dogs per pound of body weight. The reason is metabolic: cats burn protein for baseline energy even when carbohydrate is available, because their livers keep protein-processing enzymes switched permanently on. A dog downshifts protein use when dietary protein is scarce; a cat cannot, so a low-protein diet forces a cat to strip its own muscle.
Two amino acids make the carnivore case concrete. Taurine deficiency causes dilated cardiomyopathy in cats and retinal degeneration that leads to blindness, and both taurine and arginine come only from animal tissue. This is why a vegetarian cat diet is dangerous in a way a vegetarian dog diet is not.
The practical check is quick. Look for a named meat first on the ingredient list and protein at or above 26% dry matter for an adult and 30% for a kitten. When you understand the feline energy math, these percentages connect directly to a daily amount.
- Cats derive baseline energy from protein continuously, unlike dogs.
- Taurine and arginine are supplied only by animal tissue.
- Practical target: named meat first; ≥26% DM protein adult, ≥30% DM kitten.
Fat and Essential Fatty Acids (Including Coat Health)
Fat is the densest energy source at roughly 8.5 kcal per gram of metabolizable energy, and it carries arachidonic acid, an essential fatty acid that dogs synthesize but cats cannot. That inability is another line in the obligate-carnivore ledger: the cat must eat its fatty acids preformed from animal sources.
The omega-6 to omega-3 balance shows up where owners actually see it, on the skin and coat. A dull coat and dandruff are classic signals of a low-fat or low-essential-fatty-acid diet, because the cat is short on the building blocks for a healthy skin barrier. Improving dietary fat quality often resolves a lacklustre coat within weeks.
Fat also moves the portion math silently. High-fat foods pack more kcal per cup or can, so two foods at the same cup volume are able to differ sharply in calories. That is precisely why calorie density, not scoop size, sets the correct portion.
- Fat delivers ~8.5 kcal/g ME and carries fat-soluble vitamins.
- Cats cannot make arachidonic acid; they must eat it preformed.
- Dull coat and dandruff signal a low-fat or low-EFA diet.
Carbohydrates and Water: The Two Feline Outliers
Cats have no dietary requirement for carbohydrate and a limited ability to handle large carbohydrate loads. Wild prey is under 10% carbohydrate by energy, while some dry kibbles exceed 35%. The gap does not make kibble poison, but it explains why a high-carbohydrate diet fits feline biology poorly. Owners who want the full breakdown can move to calculating carbs on a dry matter basis, where the label percentages are converted to a comparable footing.
Water is the second outlier. Descended from desert hunters, cats have a low thirst drive and under-drink at the bowl, so wet food moisture compensates for the feline low thirst drive. Wet food at 70 to 80% moisture does the hydrating that a water bowl often fails to achieve, which supports urinary-tract health and helps with weight control.
This is why many veterinarians favour a wet-forward feeding pattern for cats. It is not that dry food is inadequate, but that added dietary water solves a problem the cat will not solve on its own. The canned-food amounts for cats page turns that principle into daily portions.
- No dietary carbohydrate requirement; natural prey is under 10% carb by energy.
- Low thirst drive means cats chronically under-drink at a water bowl.
- Wet food (70-80% moisture) supplies the water a bowl often does not.
Energy: How Nutrition Turns Into a Daily Portion
Nutrition answers what to feed; energy answers how much. The daily amount is driven by the resting energy requirement, calculated as RER = 70 x body-weight-in-kg raised to the 0.75 power, then multiplied by a life factor of about 1.2 for a neutered adult. A 10 lb cat lands near 260 kcal per day on that math.
Good nutrition does not exempt a cat from calorie limits. Overfeeding a complete-and-balanced food is still overfeeding, and obesity is the most common feline nutritional disease in the United States. The schedule and format divide the daily budget; they never add to it.
Once you know your cat's number, everything else is division. You can see how much to feed your cat daily and match it to the exact food in the bowl. When you are ready, see your cat's daily calorie number with the free calculator and let it turn these requirements into cans, cups or grams automatically.
- RER = 70 x kg^0.75; neutered adult factor ≈ 1.2.
- A 10 lb neutered indoor cat needs roughly 260 kcal/day.
- Obesity is the most common feline nutritional disease; portion control is the fix.
Frequently asked questions
- What makes cat nutrition different from dog nutrition?
- Cats are obligate carnivores: they need taurine, arachidonic acid and preformed vitamin A from animal tissue, plus roughly twice a dog's protein per pound. They cannot synthesize these nutrients from plant precursors the way dogs do, so dog food is deficient for cats. That is why a diet built for dogs is never a safe substitute for a cat.
- How much protein does a cat need?
- At least 26% protein on a dry-matter basis for adults and 30% for kittens, per AAFCO minimums. Many healthy feline diets run higher, in the 35-50% dry-matter range, because cats burn protein for baseline energy continuously. A named meat first on the ingredient list is a reasonable quick check.
- Do cats need carbohydrates?
- No, cats have no dietary requirement for carbohydrate. Their natural prey diet is under 10% carbohydrate by energy, and they have a limited ability to process large carbohydrate loads. Carbohydrate is not toxic, but a high-carb diet fits feline biology poorly compared with high protein and moderate fat.