Cats are obligate carnivores, meaning their bodies are built to run on animal-based protein. Their wild ancestors survived on small prey like rodents and birds, eating diets high in protein, moderate in fat, and very low in carbohydrates. Your domestic cat still needs those same general proportions today. A good cat diet prioritizes meat-based protein above all else, keeps carbohydrates low, and provides a handful of nutrients that cats simply cannot produce on their own.
Why Protein Comes First
Cats need more protein than dogs or humans because their bodies are constantly breaking down amino acids for energy, even when other fuel sources are available. This is a metabolic trait inherited from thousands of years of hunting. Industry standards set the minimum protein content for adult cat food at 26% on a dry matter basis, and food formulated for kittens or pregnant cats requires at least 30%.
Not all protein is equal, though. Plant-based proteins lack several amino acids cats depend on. Taurine is the most well-known: cats cannot synthesize enough of it internally, so it has to come from their food. A taurine deficiency can lead to serious heart disease and vision loss. Arginine is another amino acid cats must get from animal tissue. Even a single meal lacking arginine can cause a dangerous buildup of ammonia in the blood. These aren’t fringe concerns. They’re the reason meat, poultry, or fish should be the first ingredient on any cat food label.
Fat, Carbohydrates, and the Right Balance
Fat should make up at least 9% of your cat’s diet on a dry matter basis. It supplies essential fatty acids, helps absorb vitamins, and makes food taste good to cats. One fatty acid in particular, arachidonic acid, is something cats cannot manufacture from plant-based fats the way dogs can. It has to come from animal sources like poultry fat or fish oil.
Carbohydrates are the more complicated piece. Cats have limited ability to process them compared to omnivores, a quirk of their evolution as strict meat-eaters. While cats can digest and use some carbohydrates, diets heavy in them are linked to problems. Keeping carbohydrates below 25% of dry matter (or under 15% of total calories) is the general recommendation for cats with diabetes, and dietary carbohydrate restriction is associated with better blood sugar control and higher chances of diabetic remission. Even for healthy cats, lower-carbohydrate diets more closely match what their metabolism evolved to handle.
Vitamins and Minerals Cats Can’t Make
Beyond the amino acids, cats have unusually high requirements for several vitamins. They cannot convert plant compounds into usable vitamin A the way humans do. They need preformed vitamin A, which comes from animal liver and other organ meats. The same is true for vitamin D: cats lack the efficient skin-based synthesis that many mammals rely on, so dietary sources are essential. B vitamins, especially B1 (thiamine) and B12, round out the list of nutrients cats need in larger quantities than you might expect.
A complete commercial cat food will contain all of these in the right amounts. This is one of the strongest arguments against homemade or raw diets unless they’ve been carefully formulated with a veterinary nutritionist. Missing even one of these nutrients over weeks or months can cause real damage.
Wet Food, Dry Food, or Both
Wet (canned) food typically contains around 78 to 82% moisture. Dry kibble sits at about 3 to 4%. That difference matters more than most people realize, because cats evolved to get most of their water from prey rather than from drinking. Many cats on dry-food-only diets are mildly, chronically under-hydrated.
Research confirms what you’d expect: cats fed wet food produce significantly more urine and have more dilute urine than cats fed dry food. Dilute urine reduces the concentration of minerals that form crystals and stones. If your cat has a history of urinary tract problems or simply doesn’t drink much water, incorporating wet food is one of the most practical things you can do. Dry food is convenient, stores easily, and is fine for many cats, but the hydration advantage of wet food is real and measurable.
Mixing the two is a reasonable middle ground. You get the convenience of kibble with some of the moisture benefits of canned food.
How Much and How Often to Feed
Calorie needs vary by weight, age, and activity level. A common veterinary formula multiplies 30 by your cat’s weight in kilograms, then adds 70 to get daily resting energy requirements in calories. A 4.5 kg (10-pound) cat, for example, needs roughly 205 resting calories per day. Indoor, less active, or neutered cats often need just slightly above that resting number, while kittens and very active cats need more.
The calorie count is printed on every commercial cat food package, so you can measure portions accordingly. This matters because eyeballing portions is one of the fastest routes to an overweight cat, and obesity drives insulin resistance, joint stress, and a shorter lifespan. Overweight cats with diabetes that lose at least 2% of their body weight in the first month of treatment have dramatically better odds of remission, up to 15 times higher.
Free feeding, where dry food is available around the clock, works for some cats that naturally self-regulate. But many cats will overeat when food is always present. Scheduled meals, typically two per day for adults, give you direct control over portions. If you do free feed, weigh your cat regularly and adjust the amount in the bowl if the number starts creeping up.
How Much Water Cats Need
A healthy cat needs about 4 ounces of water per 5 pounds of body weight daily. That means an average 10-pound cat should take in roughly one cup of water per day, from all sources combined, including moisture in food. Cats eating mostly wet food may drink very little from a bowl and still be perfectly hydrated. Cats on an all-dry diet need to make up the difference by drinking more, and some simply won’t.
Running water fountains, multiple water stations around the house, and keeping water away from the food bowl (cats often prefer this) can all encourage drinking.
Foods That Are Dangerous for Cats
Several common human foods are genuinely toxic to cats:
- Onions, garlic, and chives damage red blood cells and can cause anemia. Cats are more susceptible to this than dogs, and even small amounts over time can be harmful.
- Chocolate and caffeine contain compounds that cause vomiting, abnormal heart rhythms, tremors, and seizures. Dark chocolate is the most concentrated source.
- Alcohol can cause vomiting, breathing difficulty, and dangerous changes in blood chemistry even in small quantities.
- Grapes and raisins are linked to kidney damage. While most documented cases involve dogs, the risk extends to cats.
- Xylitol (a sugar substitute found in gum, candy, and some peanut butters) can cause a sudden drop in blood sugar and potential liver damage.
- Salty foods in excess can lead to abnormal electrolyte levels, vomiting, and in severe cases, seizures.
Small pieces of plain cooked chicken, turkey, or fish are generally safe as occasional treats. But treats of any kind should stay well under 10% of total daily calories to avoid unbalancing the diet.
What to Look for on a Cat Food Label
The simplest thing you can check is whether the food meets nutritional standards set by AAFCO (the Association of American Feed Control Officials). Look for a statement on the package saying the food is “complete and balanced” for your cat’s life stage, whether that’s growth, adult maintenance, or all life stages. This statement means the food contains every essential nutrient in adequate amounts.
Beyond that, check the ingredient list for a named animal protein (chicken, salmon, turkey) as the first ingredient rather than a grain or plant protein. The guaranteed analysis panel will show minimum protein and fat percentages, though these are listed on an “as-fed” basis, so wet food will always look lower in protein than dry food simply because of the water content. Comparing on a dry matter basis, which removes water from the equation, gives a more accurate picture.