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The best low protein cat food addresses your cat’s health needs while providing controlled levels of highly-digestible protein. It has plenty of moisture, low phosphorus content, keeps carbohydrates to a minimum, and doesn’t contain any additives that might harm your cat.
We’ve chosen Weruva Truluxe Steak Frites as the best low-protein cat food on the market because it has controlled levels of high-quality protein, is low in carbohydrates, and contains minimal phosphorus.
Quick Look at Our Top Picks:
Weruva Truluxe Steak Frites
Royal Canin Veterinary Diet Renal Support D Morsels
Hill’s Prescription Diet k/d Kidney Care
Hi-Tor Neo Diet For Cats Review
Wellness Healthy Indulgence Shreds
Low-protein diets are not for every cat.
A low-protein diet is only recommended for cats with health conditions like kidney and liver disease. Even then, that recommendation is disputed. Modern research suggests that highly-digestible, low-residue food may be a more carnivore-appropriate alternative.
In this article, we’ll talk about the role of dietary protein for cats, which cats need a low-protein diet, and, finally, we’ll review the top 5 best low-protein cat foods on the market.
Why is protein so important for cats?
Cats are obligate carnivores. In nature, a cat has to eat animals or she’ll die. A cat might go her entire life without tasting anything that’s not an animal or part of one—and that cat wouldn’t have any nutritional deficiencies. A cat is an animal that eats other animals. Every aspect of her being is fitted to that purpose.
And when you break down an animal, what is it made of? Mostly protein. Or, on a more fundamental level, amino acids and fatty acids. Flesh and fat.
For cats, protein is life-giving. It supports lean muscle mass and gives them the energy they need to function. From the strength to pounce to the energy to purr, protein is vital to every process in your cat’s body.
How much protein does a cat need?
Cats need at least 2.36 grams of protein per pound of body weight each day.
A 2013 study found that while cats can appear healthy on about a quarter of that amount, they didn’t maintain lean muscle mass until they consumed at least 2.36 grams of protein for every pound of body weight. That translates to about 24 grams of protein per day for a 10-lb cat.
To give you an idea of what that means in terms of real food, Vital Essentials freeze-dried rabbit food provides about 27 grams of protein per day—slightly more than what cats would choose. Purina Cat Chow Complete offers 18.5 grams each day. Slightly less.
Remember though—cat food labels don’t give you the nutrient content in grams. They give you percentages. You can convert percentages to grams if you want, but if you’d prefer to keep it simple, look for food that’s roughly 50% protein, 38% fat, and 2% carbohydrates on a dry matter basis.
Cats want the amount of protein they need.
One 2011 study showed that when given the option to choose their own diet, over 100 cats consistently selected the food with 2.3 grams of protein per pound of body weight each day.
The guaranteed analysis only tells you about crude protein, but it doesn’t mention how much of that protein actually fuels your cat’s body.
For example, if your cat’s food uses a type of protein that’s only 67% digestible, those 24 grams per day could be closer to 16 grams of usable protein. The rest is waste—waste that your cat’s organs will have to work to filter out.
Protein bioavailability is a crucial part of feeding your cat well, but it’s unclear which protein sources are the most bioavailable for cats. Without a complete understanding of how cats utilize protein, it’s impossible to say which protein sources burn the cleanest.
What happens if you give your cat too little or too much protein?
In the same 2013 study mentioned earlier, cats given less than 0.68 grams of protein per pound of body weight entered a negative nitrogen balance. This meant that they were losing more nitrogen than they were taking in.
While the effects of inadequate protein intake vary based on the amino acid profile of the deficient protein, you can expect to see symptoms of malnutrition and, potentially, death. Protein malnutrition may lead to hepatic lipidosis, also referred to as fatty liver.
Most foods marketed for their low protein content are around 25% to 30% protein and provide roughly 11 to 18 grams of protein each day. Depending on your individual cat’s protein requirements, this amount may lead to loss of lean muscle mass.
Does your cat need low-protein cat food?
Some cats, usually those with kidney disease and other health problems, may benefit from protein restriction. Protein produces nitrogenous waste, which could place a burden on the kidneys or other organs.
Cats with Kidney Disease
The jury’s still out on whether protein restriction helps or hurts cats with kidney disease, but here’s what we know.
The kidneys play a crucial role in the processing of nitrogenous wastes produced by protein digestion. Since cats with kidney disease have a reduced ability to process this waste and it builds up in their bloodstream. High blood urea nitrogen (BUN) levels are a primary characteristic of kidney disease and a major part of why cats with CKD feel unwell.
To control the amount of waste in the bloodstream and ease the burden on the kidneys, cats with renal disease are traditionally given low-protein food.
This approach can help, but it can also hurt. A cat with kidney disease needs protein as much as any other cat. By restricting her protein intake, you might make your cat feel better than she did on her old diet, but you might also be helping the disease make her frail and skinny.
Some veterinarians suggest that instead of focusing on protein quantity alone, you need to think about protein quality. Highly-digestible protein, they say, is easier on the kidneys, tastes better, and it helps sick cats stay strong.
Lyn Thompson, BVSc says that “Clinically, we find that renal cats eating a raw food diet do well on highly digestible proteins like rabbit, chicken, hare and possum. Too little protein in the diet can lead to excessive weight loss that can be extremely detrimental to a cat’s general health.”
Cats with Liver Disease
Because of the liver’s role in removing the toxic by-products of protein digestion, a diet loaded with low-quality protein can strain the dysfunctional liver.
It’s recommended that cats with any type of liver disease eat food that’s rich in readily-digestible, highly bioavailable protein.
In some cases of liver disease, particularly if your cat develops hepatic encephalopathy, your veterinarian may recommend a low-protein diet. Traditionally, this has been considered a reliable way to reduce the amount of ammonia—a by-product of protein digestion— that the sick liver lets remain in the body.
More recent research, however, reveals that excessive ammonia is only a major problem if the cat is eating a diet with a lot of poorly-digestible protein. Feeding a low-protein diet may help cats feel better if they were previously on a bad diet, but protein restriction ultimately leads to muscle wasting and even worse health.
Even in cases when a low-protein diet is traditionally prescribed, the quality—not the quantity—of the protein appears to be the key to feeding a cat with liver disease.
It’s sometimes recommended that cats eat less protein as they age. The logic here is that older cats are at an increased risk of kidney disease—it’s the most common disease in cats over age 10—and therefore their kidneys need a gentle touch.
Actually, senior cats aged ten and over need more protein and more calories than they did in middle age. More than at any other stage of life, senior and geriatric cats benefit from highly-digestible, high-quality protein.
Top 5 Best Low-Protein Cat Foods
Because renal insufficiency is the number one reason a cat might need a low-protein diet, most of the following foods are prescription or non-prescription products for cats with kidney failure.
Unlike most low-protein foods—including prescription foods for cats with kidney disease—this canned food is made from high-quality animal ingredients. Not only are these ingredients carnivore-appropriate and highly bioavailable, but they’re also processed in a human food facility in Thailand.
The food is made from human-edible beef mixed with a variety of plant ingredients, including pumpkin, sweet potato, carrot, and potato starch.
The food isn’t extremely low in protein—in fact, protein accounts for about 45% of its total calorie content and just over 60% of its dry matter weight—but it provides clean protein with exceptionally low phosphorus content, a quality that makes it a good option for the cats most often given a low-protein diet.
It has 118 mg phosphorus per 100 calories or 0.57% on a dry matter basis, making it one of the lowest-phosphorus foods you can buy without a prescription. It’s low in carbohydrates with under 8% on a dry matter basis.
Water Sufficient for Processing, Beef, Pumpkin, Sweet Potato, Carrot, Potato Starch, Sunflower Seed Oil, Tricalcium Phosphate, Xanthan Gum, Choline Chloride, Potassium Chloride, Taurine, Vitamin E Supplement, Zinc Sulfate, Thiamine Mononitrate (Vitamin B1), Nicotinic Acid (Vitamin B3), Ferrous Sulfate, Calcium Pantothenate, Vitamin A Supplement, Potassium Iodide, Manganese Sulfate, Vitamin D3 Supplement, Copper Sulfate, Riboflavin Supplement (Vitamin B2), Pyridoxine Hydrochloride (Vitamin B6), Folic Acid, Vitamin B12 Supplement.
|Crude Protein||10% min|
|Crude Fat||1.3% min|
|Crude Fiber||0.5% max|
What We Liked:
- Contains highly-digestible protein
- Relatively low carbohydrate content
- Free of potentially harmful additives
- Low phosphorus content
What We Didn’t Like:
This popular food has controlled levels of phosphorus, about 30% protein, and contains anti-inflammatory fish oil to help cats with kidney disease feel better.
It’s a stew-style food featuring meaty chunks in a starch-heavy gravy. The format and flavor of the food seem to go over well with cats, even those who have lost their appetites. Most customers have positive things to say about Renal Support D, with many of them saying it’s the only prescription kidney disease food their cat will eat. Chewy reviewer Bella says that this food is the “only wet food my cat has ever enjoyed”.
Though the food is decent as far as low-protein and prescription kidney disease foods go, it’s far from the ideal cat food. It’s high in carbohydrates, contains potentially low-value animal by-products, and is generally a plant-based food.
The food’s available with a prescription only, so you’ll need to get a veterinarian’s approval before you buy it.
Water Sufficient for Processing, Chicken By-Products, Chicken Liver, Pork Liver, Wheat Flour, Vegetable Oil, Pork Plasma, Modified Corn Starch, Corn Flour, Egg Product, Glycine, Powdered Cellulose, Fish Oil, Potassium Citrate, Calcium Carbonate, Natural Flavors, Taurine, Dl-Methionine, Guar Gum, Fructooligosaccharides, Vitamins [L-Ascorbyl-2-Polyphosphate (Source of Vitamin C), Dl-Alpha Tocopherol Acetate (Source of Vitamin E), Thiamine Mononitrate (Vitamin B1), Niacin Supplement, Biotin, D-Calcium Pantothenate, Riboflavin Supplement, Pyridoxine Hydrochloride (Vitamin B6), Folic Acid, Vitamin B12 Supplement, Vitamin D3 Supplement], Salt, Citric Acid, Choline Chloride, Cysteine, Sodium Silico Aluminate, Sodium Carbonate, Marigold Extract (Tagetes Erecta L.), Magnesium Oxide, Trace Minerals [Zinc Proteinate, Zinc Oxide, Ferrous Sulfate, Copper Sulfate, Manganous Oxide, Calcium Iodate, Sodium Selenite].
|Crude Protein||6.5% min|
|Crude Fat||9.5% min|
|Crude Fiber||2.0% max|
What We Liked:
- Cats like the flavor and texture of this canned food
- Primarily made from animal protein
- Controlled phosphorus levels for cats with kidney disease
- Contains anti-inflammatory fish oil
- Free of artificial colors, flavors, and preservatives that could harm your cat
What We Didn’t Like:
- High carbohydrate content
- Available with a prescription only, making it inaccessible or impractical for some cat guardians
Like the Royal Canin food reviewed above, this is a veterinary diet available only with a veterinarian’s prescription. It addresses kidney disease in several ways. It contains reduced levels of protein—about 30% on a dry matter basis—and minimal phosphorus. It contains fish oil as a source of anti-inflammatory omega-3 fatty acids.
Hill’s claims that the food is “clinically tested to improve and lengthen the quality of life” in cats suffering from kidney disease. It achieves this by ticking all the standard kidney disease diet boxes.
Although the food has some good qualities, like straightforward, clearly-named cuts of meat instead of potentially low-value animal by-products and the inclusion of intensely nourishing pork and chicken liver, it’s not the best product you could buy.
It contains sugar as one of the first ingredients, along with brewer’s rice and modified rice starch. It’s a high-carbohydrate food that doesn’t meet your cat’s needs as a carnivore.
Water, Pork Liver, Chicken, Egg Product, Brewers Rice, Sugar, Chicken Fat, Chicken Liver Flavor, Modified Rice Starch, Powdered Cellulose, Fish Oil, Calcium Sulfate, Potassium Citrate, Guar Gum, Soybean Oil, Natural Flavor, Caramel color, vitamins (Vitamin E Supplement, Thiamine Mononitrate, Niacin Supplement, Ascorbic Acid (source of Vitamin C), Pyridoxine Hydrochloride, Calcium Pantothenate, Vitamin B12 Supplement, Vitamin A Supplement, Riboflavin Supplement, Biotin, Folic Acid, Menadione Sodium Bisulfite Complex (source of Vitamin K), Vitamin D3 Supplement), Taurine, Dicalcium Phosphate, Potassium Chloride, L-Arginine, L-Carnitine, minerals (Zinc Oxide, Ferrous Sulfate, Manganese Sulfate, Copper Sulfate, Calcium Iodate), Choline Chloride, Beta-Carotene.
Typical Dry Matter Nutrient Analysis:
What We Liked:
- Cats like the food’s paté texture and flavor
- Formulated for cats with kidney disease
- Contains fish oil as a source of anti-inflammatory omega-3s
What We Didn’t Like:
- Extremely high carbohydrate content
- Relatively low in fat
- Contains caramel color
- Available only with a veterinarian’s prescription
If you want a low-protein cat food but don’t need or want a prescription product, you might consider this food from Hi-Tor. It’s formulated to provide less protein, phosphorus, and sodium than traditional foods, but you can buy it without a vet’s approval.
The food’s protein content is around 36% on a dry matter basis, making it one of the more protein-dense foods on this list. It also has more phosphorus than your typical renal food at around 0.71% phosphorus on a dry matter basis.
Compared to the other foods on this list, this product has more vaguely-named ingredients and animal by-products. The first protein source is meat by-products. The food also contains chicken, animal liver, and ocean fish. The recipe includes a few undesirable ingredients, including carrageenan.
Sufficient Water for Processing, Meat By-Products, Chicken, Animal Liver, Beef, Poultry Fat, Ocean Fish, Rice Flour, Guar Gum, Potassium Chloride, Carrageenan, Potassium Citrate, Brewers Dried Yeast, Vitamins (E, A, D3, B12 Supplements, Thiamine Mononitrate, Niacin, D-Calcium Pantothenate, Pyridoxine Hydrochloride, Riboflavin Supplement, Folic Acid, Biotin), Minerals (Ferrous Sulfate, Zinc Oxide, Copper Proteinate, Manganous Sulfate, Potassium Iodide, Sodium Selenite), Choline Chloride, Vegetable Oil, Taurine, Iron Oxide.
|Crude Protein||8.0% min|
|Crude Fat||10% min|
|Crude Fiber||1.0% max|
What We Liked:
- A low protein food available without a prescription
- Relatively low phosphorus compared to typical cat food
What We Didn’t Like:
- High phosphorus compared to some renal foods
- Contains potentially-carcinogenic carrageenan
- High carbohydrate content
This non-prescription cat food is a bit different from the others on this list. It comes in a pouch, doesn’t contain any animal by-products or vaguely-named ingredients, is free of potentially-harmful synthetic additives, and is available without a prescription.
The food is primarily made from chicken broth and water with chicken, turkey, eggs, and chicken liver as sources of highly-digestible protein.
The food is about 26% protein on a dry matter basis. Its phosphorus content is 0.81 on a dry matter basis, making it higher in phosphorus than is generally preferred for cats with kidney disease.
Ultimately, this food is still higher in carbohydrates than we’d prefer, but of the foods on this list, it appears to have the highest quality protein and is likely one of the most digestible low-protein foods you can buy.
Chicken Broth, Water Sufficient for Processing, Chicken, Potato Starch, Turkey, Eggs, Chicken Liver, Carrots, Natural Flavor, Salt, Guar Gum, Tricalcium Phosphate, Potassium Chloride, Taurine, Magnesium Sulfate, Vitamins [Vitamin E Supplement, Thiamine Hydrochloride, Niacin, Vitamin A Supplement, Pyridoxine Hydrochloride, D-Calcium Pantothenate, Riboflavin Supplement, Folic Acid, Vitamin D3 Supplement, Biotin, Vitamin B12 Supplement], Cranberries, Blueberries, White Sweet Potatoes, Xanthan Gum, Choline Chloride, Zinc Amino Acid Chelate, Iron Amino Acid Chelate, Manganese Amino Acid Chelate, Copper Amino Acid Chelate, Potassium Iodide, Sodium Selenite.
|Crude Protein||4.0% min|
|Crude Fat||2.0% min|
|Crude Fiber||1.0% max|
What We Liked:
- Primarily made from highly-digestible animal ingredients
- Low carbohydrate content compared to other low-protein foods
- Free of potentially-harmful artificial additives
What We Didn’t Like:
- Relatively high phosphorus content
High-protein food is ideal for almost all cats.
Before you decide to cut back on your cat’s protein intake, consider your alternatives.
Even in the case of kidney disease, for which a low-protein diet is almost always prescribed, a species-appropriate amount of high-quality animal protein seems to yield better results than a low-protein diet.
Before you give your cat low-protein food, consider a diet rich in high-quality protein instead. Our article on the overall best cat food may help you make a decision.
About the author
Mallory Crusta is a writer and adventurecat enthusiast on a mission to make cats’ lives extraordinary. She’s one of the founders of Wildernesscat – a site for happy, healthy, and adventurous cats who are fueled by nature. Visit Wildernesscat for radically natural cat nutrition, home remedies, and lifestyle inspiration.