People usually land on a feeding guide like this when something feels slightly off: a cat is putting on weight, leaving food behind, vomiting hairballs more often, or suddenly developing soft stools. Sometimes it’s simpler—just the quiet question of whether the food in the bowl is actually doing the job.
A good cat diet is less about chasing “perfect” ingredients and more about meeting a few non-negotiables: enough animal-based protein, the right essential nutrients (like taurine), safe handling, and portions that keep your cat lean and steady. The most reliable check is the cat in front of you—body condition, muscle, coat, teeth, energy, and litter tray habits—paired with food that’s labelled “complete and balanced”.1, 2
What a healthy diet looks like (in real life)
Cats are obligate carnivores. They have specific nutrient requirements that are most naturally met by animal tissues, including taurine and arachidonic acid, which are essential for cats and must come from the diet.3
Rather than aiming for a particular percentage of “protein vs carbs” at home, use practical markers and a sensible product standard:
- Choose “complete and balanced” cat food as the foundation (especially for kittens, pregnant/lactating queens, and cats with health issues).2
- Keep your cat lean, with a visible waist and ribs you can feel under a light layer of flesh, not a soft pad.2
- Watch the basics: steady weight, glossy coat, normal stools, bright eyes, and comfortable movement.
If your cat has persistent diarrhoea, vomiting, itching, weight loss, marked hair loss, or a sudden change in thirst or appetite, don’t “fix it” with supplements first—book a vet check. Nutrition is part of the picture, but illness can look like diet trouble from a distance.2
A cat’s natural diet (and what that means at home)
Wild cats eat small prey—mostly mammals and birds—consuming muscle meat, organs, fat, and bone in a rough nutritional balance. Domestic cats still have the same underlying needs, but the safest way to meet them at home is usually through commercially prepared complete diets (wet, dry, or a mix), rather than trying to replicate prey with table scraps.2
Cats don’t chew like we do. They slice and tear, then swallow. That doesn’t mean they must eat large chunks, but it does mean texture matters: some cats do better with minced or pâté-style foods, while others enjoy larger meaty pieces. Dental disease, missing teeth, and arthritis can change preferences quietly over time.
About “letting a cat fend for itself”
Turning a domestic cat out without care is not a kindness; it’s neglect. Abandonment is treated seriously under animal welfare law and can lead to prosecution.4
Water: the quiet essential
Fresh water should always be available. Many cats naturally drink small amounts, especially if they eat mostly wet food, but dehydration risk rises with dry-only diets, hot weather, illness, and some medications.
- Offer multiple bowls in different spots (some cats avoid water placed right next to food).
- Keep bowls clean and refilled daily.
- If your cat is reluctant, try a pet fountain or switching some meals to wet food.
If you notice increased thirst, very large clumps in the litter tray, or weight loss, seek veterinary advice—kidney disease and diabetes are common culprits in older cats.
Vitamins and minerals: where this article needed updating
Vitamins and minerals are essential, but “more” is not safer. The simplest way to avoid both deficiency and excess is to feed a diet formulated to meet recognised standards and to be cautious with supplements unless your vet recommends them.2
Vitamin A
Cats cannot convert beta-carotene (from carrots and many vegetables) into vitamin A efficiently. They need preformed vitamin A from animal sources in the diet, which is one reason “complete and balanced” foods matter—especially for kittens and breeding cats.3
Vitamin C
Unlike humans, cats can synthesise vitamin C in their bodies, so it isn’t usually required as a dietary supplement for healthy cats.3
Vitamin D
This is where old advice often goes wrong. Cats do not reliably synthesise enough vitamin D through sunlight exposure the way people do, so vitamin D must come from the diet. Because vitamin D toxicity is possible, supplementation should be veterinary-guided rather than improvised at home.3
Carbohydrates, vegetables, fruit and grass
Cats don’t have a nutritional requirement for carbohydrates, but small amounts can be included in commercial diets for processing and energy. The priority is still adequate animal-derived protein and essential nutrients (especially taurine).3
Vegetables and fruit are optional extras. If offered, keep portions small and avoid anything known to be unsafe for cats. When in doubt, don’t guess.
Many cats nibble grass. It may act as roughage, and vomiting after grass-eating is common. Repeated vomiting, gagging, constipation, or signs of pain are not “normal hairballs” and deserve a vet check.
Fats
Dietary fat supplies energy and essential fatty acids. Cats also require arachidonic acid, which is found in animal tissues and is another reason cats cannot thrive on a plant-only diet.3
Avoid giving butter, margarine, and “fatty scraps” as routine nutrition. They add calories quickly and can worsen gastrointestinal upset in some cats.
Protein: how much, and why quality matters
Cats do need a protein-rich diet, but the useful target isn’t a home-made percentage—it’s whether the overall diet is complete, appropriate for life stage, and keeping your cat lean with good muscle. Look for foods formulated for kitten/growth, adult maintenance, or all life stages, and avoid making meat-only feeding the default unless a veterinary nutritionist has formulated the recipe.2
Meat alone (even “good” meat) is not a complete diet for cats. Without careful formulation, deficiencies can develop over time, and some nutrients can drift dangerously high.
Meat and offal: sensible use at home
Cooked, plain meats can be used as occasional toppers or treats, but they should not displace a balanced diet. Liver and other organs are nutrient-dense and can cause problems if fed frequently in large amounts (especially vitamin A excess), so keep organ meats as a small, occasional addition unless your vet has prescribed otherwise.3
If you handle raw meat for any reason, practise strict kitchen hygiene and keep cat utensils separate from human food preparation.
Fish: helpful, but not a main diet
Many cats love fish, but fish-based feeding has some traps: certain raw fish can contain thiaminase (which can reduce thiamine), and fish-only diets can become unbalanced. Fish works best as a flavour, a rotation option in complete foods, or an occasional treat—rather than the whole menu.
Eggs, cheese and milk
Eggs
Cooked egg can be an occasional high-quality protein treat. Avoid feeding raw egg whites regularly, as avidin can interfere with biotin over time.
Cheese
Cheese is rich and salty. Some cats tolerate small amounts, but it’s best treated as an occasional treat, not a protein strategy.
Milk
Many adult cats are lactose intolerant and may develop diarrhoea after cow’s milk. If you want to offer something “milky”, use a cat-specific lactose-reduced product or simply offer extra wet food for hydration support.5
Prepared cat foods: the safest foundation for most homes
Commercial cat foods (wet or dry) are formulated to meet nutrient requirements when they’re labelled as complete and balanced. This matters because cats have very specific needs, including taurine, and deficiencies can cause serious disease over time.2, 6
Practical notes:
- Wet food increases water intake and is often useful for cats prone to urinary issues or constipation (your vet can advise for your cat).
- Dry food is convenient and can be left out longer, but it’s calorie-dense—measure portions rather than free-feeding by default.
- If you switch foods, transition gradually over several days to reduce stomach upset.
Raw diets: proceed with care
Raw feeding is popular, but it carries two recurring risks: pathogens (for people and pets) and nutritional imbalance, especially with home-made recipes. If you choose a raw diet, look for a clear nutritional adequacy statement and discuss the plan with your vet—particularly for kittens, pregnant/lactating queens, senior cats, or immunocompromised pets and people in the household.7
Supplements and treats
Supplements are not automatically harmless. The safest approach is:
- Use treats to build routine and enjoyment, not to “patch” nutrition.
- Keep treats to a small share of daily intake (especially for indoor cats).
- Only add vitamins/minerals when a vet has identified a need.2
Important: chocolate is toxic to cats and should not be offered as a treat.8
How much to feed
Portion size depends on age, body size, desexing status, activity level, and the energy density of the food. Instead of relying on a single grams-per-kilo rule, use two anchors:
- Start with the feeding guide on the packet (it’s based on the food’s calorie density).
- Adjust every 2–3 weeks based on body condition score and steady weight trends.2
If weight is creeping up, reduce calories gently and add play and foraging-style feeding. If weight is dropping without a deliberate diet change, treat it as a medical clue and see your vet.
Feeding by life stage
Kittens
Kittens need high energy and nutrient-dense food formulated for growth, offered in multiple small meals. Choose a complete kitten diet and keep fresh water available.2
Pregnant and lactating queens
Queens need markedly higher energy intake during late pregnancy and especially lactation. Feed a complete growth or reproduction-appropriate diet, offer food more frequently, and monitor body condition so she doesn’t become depleted.2
Neutered cats
After desexing, many cats need fewer calories. Keep meals measured, prioritise play, and watch the waistline rather than the bowl.
Senior cats
Older cats may lose muscle more easily and may develop dental disease, arthritis, kidney disease, or hyperthyroidism. Soft textures can help when teeth are sore, but appetite or weight changes should be assessed by a vet rather than written off as “just age”.2
Sick cats and prescription diets
For medical conditions (kidney disease, diabetes, urinary crystals, pancreatitis, food allergy), diet can be part of treatment, but the right plan depends on diagnosis and the individual cat. Don’t trial restrictive diets without veterinary guidance—well-meant changes can backfire.
Editor’s note: The FAQ shortcode below has been left in place for your CMS to render.
References
- WSAVA Global Nutrition Guidelines (World Small Animal Veterinary Association)
- WSAVA Global Nutrition Toolkit resources (diet history, BCS, calorie guidance)
- Nutrient Requirements of Dogs and Cats (National Research Council)
- RSPCA NSW: Abandonment/neglect prosecution example (animal cruelty case summary)
- Merck Veterinary Manual: Diarrhoea in small animals (dietary intolerance including lactose)
- Cat nutrition overview and taurine as an essential nutrient (Pet Food Institute)
- VCA Animal Hospitals: Avoiding raw food in cats (pathogen and balance risks)
- ASPCA: People foods to avoid (includes chocolate toxicity)
Veterinary Advisor, Veterinarian London Area, United Kingdom