Plant Protein as a Diet Choice for Cats

Plant Protein as a Diet Choice for Cats

In recent years, there has been a surge of interest in alternative diets for our furry friends. It makes a ton of sense. Cat owners are, at large, animal lovers and many choose to be vegetarian. For this same reason many pet owners are exploring the possibilities of vegetarian, insect-based, and plant-based diets for their cats.

As a veterinarian and animal nutritionist, my primary concern is the well-being of your cat. It's essential to navigate these dietary choices with caution, especially considering the unique nutritional needs of cats.

In this article, we will delve into the complex and sometimes contentious topic of plant-based protein in cat diets.

Cats have evolved as obligate carnivores, meaning their natural diet primarily consists of animal-based proteins. As such, their bodies have specific nutritional requirements that differ significantly from those of omnivorous animals like humans.

Vegetarian lab meat is now very real and many humans (including myself) choose to eat it. The idea of providing your cats with a plant-based diet seems like a conscientious choice for various reasons, including ethical and environmental concerns.

Does such a diet truly align with a cat's biological needs?

Let’s dig into this amazing topic together!

The Natural Diet of Cats

Cats are quintessential carnivores, and their evolutionary history reflects this carnivorous nature. Unlike omnivorous animals, their ancestors thrived on a diet primarily composed of animal flesh.

Cat Carnivore eating Meat

This carnivorous lineage has profoundly shaped their digestive systems, metabolic processes, and overall nutritional requirements.

The Anatomy/Physiology That Makes Cats Obligate Carnivores

There are several specific digestive anatomic and physiologic adaptations of cats to a strictly carnivorous diet:

  • Anatomic Features: The intestinal length of cats is markedly shorter in cats than in omnivores and herbivores. Therefore, cats can less efficiently use vegetables, which require longer digestion time than animal tissues.
  • Digestion Physiology: Cat’s digestive systems are not well-suited to process large amounts of carbohydrates like starches and sugars. They lack salivary amylase, an enzyme needed to break down starches, and their small intestines and enzymes are adapted for low-carb diets. Their pancreas produces very little amylase compared to omnivorous animals, indicating a lack of adaptation to significant dietary carbohydrate changes.

These emphasize that a cat's natural diet is centered around animal proteins, and introducing high levels of plant-based carbohydrates may not align with their digestive capabilities or evolutionary history.

What about Plant Proteins?

When it comes to feline nutrition, understanding the differences between plant-based and animal-based proteins is crucial.

Animal-based proteins, derived from sources like meat, fish, and poultry, offer a complete array of essential amino acids, which are the building blocks of proteins. These proteins are well-matched to a cat's dietary needs and are highly digestible.

Cat Balanced Diet

In contrast, plant-based proteins, sourced from ingredients like soy, peas, and lentils, tend to have incomplete amino acid profiles for cats. This means they lack certain essential amino acids in sufficient quantities, making it almost impossible to meet a cat's nutritional requirements solely from plant sources.

To bridge this gap, commercial pet food manufacturers use a combination of plant proteins and synthetic additives to create a more balanced amino acid profile.

Probably at this point, you are wondering yourself:

Can cats survive on a plant-based diet?

Yes. Cats can survive on a plant-based diet. Always the plant-based diet is completed with the lacking required nutrients for cats.

What Happens When Cats Get Their Protein from Plants?

In commercial pet foods marketed as plant-based or vegetarian, common plant protein sources include soybean meal, pea protein, and lentil protein.

These ingredients are chosen for their relatively high protein content and affordability. However, it's important to note that they may not provide all the necessary nutrients cats require without additional supplementation.

But, nutritionally speaking, what are the differences between things like whole grains, beans/legumes, and plant protein concentrates (like potato or pea protein) for cats?

Nutritionally speaking, these are very different products!

Whole grains, beans, and legumes are natural vegetables (without any (or very simple) processing). The nutritional analysis of these food ingredients can be defined like:

Mean nutrient composition

Whole grains

Beans and legumes













Vitamins and minerals



Mean values from Nutrient Optimizer Org.

Plant protein concentrates are isolated proteins from natural vegetables. So, the manufacturers remove the carbohydrates, fats, and fibers (and also minerals and vitamins) from the vegetables to obtain a product that is 100% protein.

Like this can sound great thinking in cat nutrition (we don’t have the difficult-digest carbohydrates), we must take into account that the final product is an ultra-processed by-product, which also has lost some important nutrients contained in whole grains, beans, and legumes (like essential minerals and vitamins).

The Risks of Plant-Based Diets for Cats

Plant-based diets for cats come with inherent risks and challenges that need to be carefully considered:

  • Nutrient Deficiencies: Plant-based diets may lack vital nutrients such as taurine, arachidonic acid, omega 3 fatty acids, vitamin D, and vitamin B12, which are primarily found in animal-based sources. Deficiencies in these nutrients can lead to serious health problems, including heart disease, vision impairment, and neurological issues.
  • Digestive Problems: Cats may struggle to digest and absorb plant-based ingredients efficiently, leading to gastrointestinal discomfort and potential nutrient malabsorption.
  • Weight Management: The higher carbohydrate content in many plant-based diets can contribute to weight gain and obesity in cats, increasing the risk of associated health problems.

Alternatives to Plant-Based Diets

While plant-based diets may not align with a cat's natural nutritional requirements, there are alternative dietary options that prioritize animal-based proteins and provide a more suitable solution for your cat:

  1. High-Quality Animal-Based Diets: Consider feeding your cat a high-quality commercial cat food that is primarily composed of animal-based proteins. Look for products that list meat, poultry, or fish as the main ingredients. These diets are formulated to meet the specific nutritional needs of cats and are a reliable way to ensure your cat friend gets the essential nutrients they require.

There is a wide range of formats available like dry kibble and canned wet food. However, my advice is always to choose a wet or raw option to increase the hydration of your cat.

Raw Diet for Cats

If you want to dig deeper in this crucial issue for your cat’s health, don’t miss our blog article The Importance of Water Intake and Hydration for Cats.

  1. Raw or cooked Homemade Diets: Some cat owners opt for raw or cooked homemade diets that closely mimic a cat's natural prey. These diets typically consist of meat, organs, and bones. While they can provide a species-appropriate diet, it's crucial to consult with a veterinarian or animal nutritionist to ensure these diets are balanced and safe for your cat.

If you want to know the first steps of Mia being a raw eater, read our blog article I Started Feeding my Cat Raw. YOU SHOULD TOO!.

The Importance of Veterinary Guidance

Before making any significant dietary changes for your cat, it is paramount to consult with your veterinarian. They can conduct a thorough examination, review your cat's medical history, and offer tailored dietary advice.

Whether you are considering commercial cat food or contemplating a homemade cooked or raw diet, your veterinarian can collaborate with you to design a balanced and safe meal plan that meets your cat's specific nutritional requirements.

Take home message

Administer a diet that is not complete and balanced in nutritional terms, or a diet that is not easy to digest (diets high in ultra-processed ingredients and carbohydrates), especially when they are administered chronically, can cause severe health problems in our beloved pets.

Currently, we are detecting a huge increase in metabolic diseases (like obesity and diabetes) in the pet population due to the inappropriate diet we are offering to our animals.

My advice is always to consider that we are co-living with little carnivores (despite they look so cute and inoffensive to our eyes), and providing the most biologically appropriate and high-quality diet is our obligation as pet parents to ensure their health and well-being.


Neus Torrent

Veterinarian & Animal Nutritionist

Leave a comment

Please note, comments must be approved before they are published

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.