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Protein is a key component of a balanced feline diet. But how much protein does your cat need? It depends on numerous factors including your cat’s life stage, the type of diet, and the quality of the protein in it.
In this guide, we’ll discuss the importance of protein in your cat’s diet and talk about how to estimate their individual requirements. We’ll also review the protein recommendations offered by various trade associations and how they impact commercial cat food formulation. Finally, we’ll offer simple tips for meeting your cat’s protein requirements.
Let’s start by exploring the importance of protein in your cat’s diet.
Why Protein Is Important for Cats
You don’t have to be a veterinarian to understand the basics of feline nutrition. After all, your cat needs many of the same nutrients you do, though the form and necessary dietary concentration may differ. Take protein, for instance.
You probably already know that protein plays a key role in building and maintaining lean muscle mass. That’s why it’s so vital for kittens who are still growing and developing. But if you really want to dig into the details, it’s essential to understand that it’s not just protein cats need—it’s the amino acids they’re composed of.
As you may recall from grade school science class, amino acids are the building blocks of proteins.
About 500 amino acids have been found in nature but only 21 of them make up all the proteins in the feline body. Your cat’s body can synthesize 10 of these amino acids from other materials but the remaining 11 need to be obtained from their diet—these are called essential amino acids.
The 11 essential amino acids for cats include:
Taurine
Arginine
Histidine
Isoleucine
Leucine
Lysine
Methionine
Phenylalanine
Threonine
Tryptophan
Valine
The combination of essential and non-essential amino acids is what enables your cat’s body to build and repair muscles, cartilage, bones, skin, fur, and claws, as well as vital organs like their heart. Amino acids are also used to create the hormones and enzymes that facilitate key bodily functions like metabolism, digestion, and immunity.
Practically speaking, protein can also be used as an energy source, and it increases the palatability of a cat’s diet. Remember, cats are carnivores, so their ideal diet is meat-based.
How To Determine Your Cat’s Protein Requirements
Choosing the right cat food product is a matter of determining your cat’s individual requirements. BearFotos / Shutterstock.com
The first step in determining how much protein your cat needs is to identify their life stage. Kittens and juvenile cats who are still developing—as well as pregnant and lactating females—have higher protein requirements than adult cats. They need higher concentrations of amino acids to build healthy tissue as they grow. But adult cats need a specific amount of protein too.
Proteins in the body naturally degrade and need to be replaced over time. In a diet for mature cats, protein supplies the necessary amino acids to maintain balance. If the diet is deficient in amino acids, the body may start breaking down muscle tissue to meet the demand for protein.
To summarize, most cats have similar minimum requirements for dietary protein based on their life stage. There are two ways to quantify this requirement:
Grams of protein per 1,000 kcal of dietary intake
Percent concentration of the diet (measured as dry matter)
This is where things get a little tricky. Research into the nutritional requirements of cats is limited and, to some degree, outdated. Plus, recommendations vary among the most trusted organizations that publish dietary recommendations (which commercial pet food manufacturers then use to formulate their recipes).
Here’s a breakdown of official protein recommendations for cats:
Organization
Who They Are
Protein Recommendation (grams per 1000 kcal)
Protein Recommendation (% Dry Matter)
National Research Council (NRC)
The operating agency of the National Academies of the USA, a private non-profit organization that carries out scientific studies and makes their findings available to the public.
40g per 1,000 kcal (Adult)
26% DM (Adult)
45g per 1,000 kcal (Growth & Reproduction)
30% DM (Growth & Reproduction)
Association of American Feed Control Officials (AAFCO)
A private voluntary organization made up of feed industry officials that makes recommendations to guide the formulation, manufacture, and labeling of pet foods.
65g per 1,000 kcal (Adult)
26% DM (Adult)
75g per 1,000 kcal (Growth & Reproduction)
30% DM (Growth & Reproduction)
European Pet Food Industry Federation
(FEDIAF)
A trade body made up of representatives from five major European pet food brands that offers nutritional guidelines and helps manufacturers meet relevant legislation requirements.
62.5g per 1,000 kcal (Adult)
25% DM (Adult)
70g per 1,000 kcal (Growth)
28% DM (Growth)
75g per 1,000 kcal (Reproduction)
30% DM (Reproduction)
If you want to simplify the above recommendations as much as possible, you could say that most cats need at least 3-4 grams of protein a day per kilogram of body weight. That’s about 20-30% of their daily calories from protein.
That said, it’s important to keep in mind that these values are supposed to be minimum requirements. And remember, they’re based on research that could use an update.
The NRC values listed in the table above come from a 2006 update to guidelines first developed in the 1960s—guidelines that were largely based on research conducted on agricultural animals. It wasn’t until the 1980s that the NRC adjusted the recommendations after conducting more focused research on cats and dogs. Both AAFCO and the FEDIAF use NRC research as the foundation for their recommendations.
The results of a more recent (but limited) study conducted in 2013 suggest the minimum daily protein requirement for adult cats is at least 5.2g per kilogram of body weight. That’s about 81g per 1,000 kcal (32% protein DM) or 30-40% of your cat’s daily calories.
Many experts recommend a minimum protein intake of 5-6 grams per kilogram of body weight daily. For example, a 4.5 kg (10-pound) cat would need at least 22.5-27 grams of protein daily.
This value comes a little closer to the protein content of a wild feline diet, in which about 50% of the calories come from protein. If you’re striving to approximate the nutritional breakdown of a wild prey diet for your cat, you may want to aim higher than NRC, AAFCO, and FEDIAF protein minimums.
How Much Crude Protein Should Be in Cat Food?
Adult cats require a diet containing at least 26% dry matter protein. Marina Demidiuk / Shutterstock.com
If you find yourself a little confused at this point, I don’t blame you. The pet food industry is constantly changing and existing regulations don’t always reflect current research.
The good news is that you don’t have to obtain a degree in science to be a responsible cat owner. If you just want to make sure your cat’s basic nutritional needs are being met, most commercial cat food products will do the trick.
On average, commercial dry cat food contains 30-40% crude protein on a dry matter basis. Wet cat food usually ranges from 8-12% crude protein or 40-50% when converted to dry matter.
Some commercial cat foods are better than others but any product that meets AAFCO guidelines is going to be closer to ideal than an unbalanced homemade diet or poorly formulated commercial cat food.
If you want to keep things simple, here are the points to focus on when reading a cat food label.
AAFCO Statement of Nutritional Adequacy
Most cat food manufacturers in the United States use AAFCO nutrient guidelines to formulate their products. If a label carries an AAFCO statement of nutritional adequacy, it tells you two things.
First, it verifies that the product meets the minimum protein requirements listed in the table above. Second, it lets you know what life stage the product is formulated for: adult maintenance, growth and reproduction, or all life stages. Make sure it matches your cat’s life stage.
Guaranteed Analysis
The guaranteed analysis is the table on a cat food label that gives you the product’s percentage breakdown of crude protein, crude fat, crude fiber, and moisture. Keep in mind these values are listed on an as-fed basis—you’ll need to convert them to dry matter values if you want to make a direct comparison between different food types.
As a reminder, cat food formulated for kittens (and pregnant or lactating female cats) should contain at least 30% dry matter crude protein. Adult cats need at least 26% dry matter crude protein. To convert as-fed values to dry matter, plug the protein and moisture values into an online dry matter calculator.
Ingredients List
If you want to take things one step further, check the list of ingredients to determine whether the product’s protein content comes primarily from animal or plant sources. As carnivores, cats are biologically adapted to efficiently absorb and utilize nutrients from animal sources.
Let’s talk a little more about the type of protein that’s best for cats.
What Protein Is Best for Cats?
Protein content is a helpful metric to use when shopping for cat food, but a percentage in the guaranteed analysis table doesn’t tell you the whole story. Some cats may need more than the minimum recommended level of protein depending on the specific diet they’re eating.
Now we’re talking about protein quality.
A cat food product that barely meets those minimum protein requirements I keep mentioning is more likely to be adequate when the protein quality of the diet is high. When protein quality is low, a diet that meets that 26% or 30% dry matter minimum might not be sufficient.
Protein quality is determined by three factors:
Amino acid profile
Digestibility
Biological value
Let’s take a closer look at these factors.
1. Amino Acid Profile
Remember those essential and non-essential amino acids we talked about earlier? Here’s where they really come into play. A high-quality protein source for cats is one that contains the complete list of essential amino acids—this is called a complete protein.
All animal-based proteins (like poultry, meat, fish, and eggs) are considered complete proteins for cats. Plant-based proteins may contain essential amino acids, but not all of them and generally in lower quantities than animal-sourced proteins.
2. Digestibility
A protein’s value is limited by your cat’s ability to break it down into usable amino acids. Again, animal proteins are generally more digestible for cats than plant proteins. But in this case, we also need to assess the digestibility of the product as a whole.
As carnivores, cats have much shorter digestive tracts than plant-eating mammals. Herbivores need long digestive tracts and higher concentrations of fermenting bacteria in the gut to break down tough plant materials. The prey wild cats are adapted to eating is composed primarily of easily digestible protein and fat.
Increasing the carbohydrate content of a cat food product may reduce its overall digestibility and, thus, the digestibility of the protein. The same concept may apply to high-fiber cat food. High-heat processing methods and synthetic additives may affect digestibility as well.
3. Biological Value
Whereas digestibility refers to the ease with which your cat’s body can break down a protein source, the biological value applies to their ability to efficiently utilize the individual amino acids. The two are not necessarily linked—it’s possible for a protein to have low digestibility but high biological value.
Again, animal ingredients generally have the highest biological value for cats. That said, recent research suggests cats may be able to utilize plant protein more efficiently in concentrated forms like soy protein isolate or corn gluten meal. The results of the study in question revealed increased overall protein digestibility in cats fed an extruded diet that contained both animal protein and plant protein concentrated from soybeans, corn, or rice.
When it comes to choosing a diet for your cat, you can make it as simple or as complicated as you like. That said, nutritional balance is non-negotiable if you want your cat to be healthy. When in doubt, start with an AAFCO-approved product and ask your veterinarian for advice.
Frequently Asked Questions
Should cats eat a lot of protein?
Yes, a diet rich in high-quality animal protein is essential for your cat to thrive. While most cats can benefit from a diet that exceeds the minimum requirements established by the NRC, AAFCO, and FEDIAF, the focus should be on the quality and digestibility of the protein rather than simply feeding large quantities.
What happens if cats don’t get enough protein?
Inadequate protein intake can contribute to stunted growth and poor development in kittens. In adult cats, a low-protein diet may lead to loss of muscle mass and poor coat condition as well as heart and vision problems. An unbalanced diet can also impact your cat’s immunity and put them at risk for serious health problems.
How do I add more protein to my cat’s diet?
The simplest options are to switch to a diet that contains a higher dry matter percentage of crude protein or to a product that contains higher quality protein. You can also supplement your cat’s daily diet with high-protein meal mixers or toppers like freeze-dried cat food, bone broth, or even cooked poultry, meat, or fish.
Is high protein bad for senior cats?
High-quality protein from animal sources isn’t harmful for senior cats. In fact, senior cats may need extra protein to maintain lean muscle mass. Though the subject is still somewhat controversial, there is no conclusive evidence to support protein restriction in senior cats and cats with kidney disease.
That said, certain high-protein diets may contain excessive levels of minerals like phosphorus which can be problematic for cats with kidney disease.
