UNDERSTANDING YOUR FELINE COMPANION
Lucia Fernandes, Feline Behavior and Environmental Enrichment Specialist (CoE, Oplex Certified)
Cat Nutrition Basics: What Cats Really Need to Thrive
A science-based guide for everyday cat parents.
As a feline behavior and nutrition specialist, one of the patterns I see most consistently is this: behavior problems and nutrition problems are rarely separate issues.
Cats that struggle with litter box avoidance, aggression, anxiety, or chronic stress are often cats whose diet is working against their biology rather than supporting it.
This guide explains what cats genuinely need to eat, why most commercial diets fall short, and how small dietary changes can improve not just physical health but emotional stability too.
If you are already dealing with litter box problems, it is worth reading about how nutrition and litter box behavior are connected before making changes.
Cat Nutrition Essentials - At a Glance
1. Cats Are Obligate Carnivores — What That Really Means
Cats did not evolve to eat grains, starches, or plant-based proteins. They evolved to eat whole prey, small animals that are roughly 70–75% moisture, high in animal protein, rich in essential amino acids like taurine, and almost entirely free of carbohydrates.
This is not a preference. It is a biological requirement.
When a cat's diet consistently departs from this, which most dry-food-based diets do, the body adapts in the short term but pays a price over time. Urinary crystals, chronic kidney disease, obesity, diabetes, constipation, and stress-related behaviors are all conditions that appear more frequently in cats fed diets that don't match their biology.
The good news is that understanding this principle makes everything else in feline nutrition much clearer.
Cats evolved to eat prey that is:
• 70–75% moisture
• High in animal protein
• Rich in essential amino acids: taurine
• Very low in carbohydrates
This is why most diets today create problems nutritionally such as:
• Urinary crystals
• Chronic Kidney Disease
• Obesity
• Constipation
• Diabetes
• Stress-related behaviors
2. Wet Food: The Closest to Their Natural Diet
Of the commercial options available, wet food comes closest to what a cat's body is designed to process. It is high in moisture, typically higher in animal protein than dry food, and lower in carbohydrates.
This matters because cats have a low thirst drive, they are designed to get most of their hydration from food, not from a water bowl. A cat eating dry food exclusively must drink significantly more water than most cats naturally will, which places ongoing stress on the kidneys and urinary tract.
Wet food is particularly important for cats with urinary concerns, kidney disease, constipation, diabetes, obesity, or any history of litter box problems related to discomfort or pain. For a full comparison of wet and dry options, see our guide to the Best Food for Cats.
Wet food supports:
• Urinary health
• renal function
• Digestion
• Weight management
• Hydration: This is very important.
Best for: Most cats, especially those with urinary concerns, dehydration, constipation, diabetes, obesity, kidney disease, or stress.
3. Dry Food: When It Works and When It Doesn't
Dry food is convenient, affordable, and easy to store, which is why it became the default for so many cat owners. But it has real limitations that are worth understanding.
Kibble typically contains only around 10% moisture, compared to the 70–75% found in natural prey. It is also usually high in carbohydrates, even grain-free versions often replace grains with peas, potatoes, or tapioca, keeping the starch content high.
Over time, diets based primarily on dry food are associated with chronic dehydration, urinary crystals, kidney stress, weight gain, and constipation. These are not inevitable outcomes, but they are risks worth taking seriously.
If you feed kibble, combining it with wet food, choosing high-protein formulas with named meat as the first ingredient, and ensuring fresh water is always available will reduce many of these risks.
Benefits
• Easy to use
• Affordable
• Long shelf life
Disadvantages
• only 10% moisture
• high in carbohydrates often contains fillers, dyes, sugar
• encourages overeating
• linked with dehydration and urinary problems
If you choose to feed kibble:
-
Combine it with wet food
-
Choose grain-free or high-protein formulas
-
Add hydration: water or broth
4. Grain-Free Diets: What the Label Actually Means
Grain-Free Benefits:
• more protein
• Fewer allergens
• Less digestive stress
Grain-Free Risks
Some brands replace grains with potato or tapioca and they still high in carbs.
Recommendation:
Always check the ingredient list. Protein should be #1 and preferably animal-based.
Grain-free has become one of the most common marketing terms in the pet food industry, but it does not automatically mean better. What cats need is not simply the absence of grains, it is the presence of high-quality animal protein as the primary calorie source.
Many grain-free formulas replace wheat or corn with peas, lentils, potatoes, or tapioca. These ingredients keep carbohydrate levels high while giving the impression of a more natural diet. The label says grain-free. The ingredient list tells a different story.
When evaluating any cat food, grain-free or otherwise, the ingredient list matters more than the front of the packaging. Animal protein should appear first. If plant-based ingredients dominate the first five, the formula is unlikely to meet your cat's biological needs regardless of what the packaging claims.
5. Raw Diets: Excellent but Require Professional Balance
A raw diet can:
• Improve digestion
• Improve coat and skin
• Help with allergies
• Support muscle
• Encourage natural chewing behavior
BUT…
It requires:
• Strict hygiene to avoid cross contamination
• Nutritional balancing
• Veterinary oversight
Not all cats tolerate raw, and not all homes are suitable.
A properly balanced raw diet is often considered the gold standard in feline nutrition, closest to what cats evolved to eat, highest in bioavailable protein, and free from the processing that degrades nutrients in commercial food.
The results, when done well, are often visible: improved digestion, better coat condition, healthier weight, and in many cases, calmer and more stable behavior.
But raw feeding requires care. To be safe and nutritionally complete, a raw diet needs correct calcium-to-phosphorus ratios, adequate taurine, appropriate vitamins and minerals, and careful handling to prevent bacterial contamination. Without these, raw feeding can cause nutritional deficiencies or health risks rather than preventing them.
For most cat owners without a background in feline nutrition, starting with commercially prepared raw food, which is formulated and tested for balance - is a safer entry point than home-prepared raw.
If your cat has existing health conditions, speak with your vet before transitioning.
6. Feeding Routines That Support Behavior and Emotional Balance
Top feline specialists agree,
Best daily routine:
• 2–3 wet food meals
• Small portion of high-quality kibble
• Fresh water always available
This supports:
• Calm behavior
• Reduced begging for food
• Better controlled weight
• Predictable routine for the cat. This leads to a better litter box habits
How and when you feed your cat matters as much as what you feed.
Cats are crepuscular animals, naturally most active at dawn and dusk, which aligns with typical hunting patterns. Two to three scheduled meals per day, timed around these natural activity peaks, tend to produce calmer behavior, better digestion, and more predictable litter box habits than free-feeding or irregular schedules.
Predictability reduces stress. A cat that knows when food is coming is a cat that doesn't need to spend energy anticipating or managing uncertainty. This is particularly relevant for cats showing anxiety, excessive vocalization around mealtimes, or litter box irregularity.
For cats in multi-cat households, separate feeding stations reduce competition and the low-level stress that often goes unnoticed but accumulates over time. This is one of the environmental changes most likely to have an effect on litter box behavior in homes with more than one cat.
7. Nutrition and Behavior: The Connection Most Owners Miss
Poor nutrition can trigger:
• Litter box avoidance
• Aggression
• Irritability and Anxiety
• Over-grooming
• Stress behaviors
A biologically appropriate diet stabilizes mood and reduces stress.
This is the section most cat owners don't expect.
Nutrition affects behavior directly, not just through physical health, but through mood, stress tolerance, and emotional regulation. A cat whose biological needs are chronically unmet is a cat whose nervous system is under ongoing strain. That strain shows up in behavior.
Litter box avoidance is one of the most common consequences of diet-related discomfort, particularly when urinary inflammation or constipation makes elimination painful. The cat associates the box with pain and stops using it. This is not a training problem. It is a health response.
Poor nutrition can also contribute to irritability, over-grooming, anxiety, heightened reactivity, and what owners often describe as aggression "out of nowhere."
If your cat is showing any of these behaviors, it is worth considering diet as a contributing factor before focusing solely on behavioral intervention.
Understanding why cats avoid the litter box is a good place to start if elimination problems are part of what you're navigating.
For a deeper look at how behavior and health intersect, explore Cat Behavior Problems or learn about Anxiety in Cats.
Frequently Asked Questions
What is the best overall diet for most cats?
Most cats thrive on a moisture-rich, high-protein, meat-based diet with very few carbohydrates. This mimics natural prey, which is roughly 70–75% water and rich in animal protein and taurine. Wet food or a properly balanced raw diet usually comes closest to this ideal for most households.
Are dry foods bad for cats?
Dry food is not automatically harmful, but it is low in moisture and often high in carbohydrates. Over time this can contribute to chronic dehydration, urinary crystals, kidney stress, obesity, and constipation. If you use kibble, it is safer as part of a diet that also includes wet or high-moisture food.
Why is moisture so important?
Cats evolved as desert animals with a naturally low thirst drive. They are designed to get most of their hydration from food. Feeding mostly dry food means your cat must compensate by drinking significantly more water than most cats naturally will, and most don't. The kidneys, bladder, and urethra bear the consequences over time.
How should I transition my cat to a new food?
Transition slowly over 7 to 14 days. Start with roughly 10–20% new food mixed into the old, and increase gradually every one to two days as long as digestion remains stable. Go more slowly with anxious cats or those with sensitive stomachs. Rushed transitions commonly cause vomiting, refusal, and diarrhoea.
Related Resources
If you found this guide useful, these pages explore related topics in more depth:
Best Food for Cats - Detailed comparison of wet, dry, and raw options with practical recommendations
Litter Box Problems - How diet, hydration, and health intersect with elimination behavior
Why Cats Avoid the Litter - Box Medical and behavioral causes, including diet-related discomfort
Senior Cat Care - How nutritional needs change as cats age
Anxiety in Cats - How stress, environment, and diet affect emotional regulation
Final Thought
Nutrition is rarely the first thing cat owners consider when behavior problems appear. It is usually the last.
But what a cat eats shapes how they feel. physically and emotionally. A cat in chronic low-grade discomfort from dehydration, urinary inflammation, or digestive stress is not a cat that can feel settled, confident, or emotionally regulated. That discomfort shows up somewhere. Sometimes in the litter box. Sometimes in behavior that looks like aggression or anxiety. Sometimes in withdrawal that gets dismissed as the cat "just being independent."
You don't need to overhaul everything at once. Small, consistent shifts, more moisture, better protein sources, a predictable feeding routine, can make a meaningful difference over time. If you're navigating behavior challenges alongside dietary questions, the resources below are a good place to continue.