The Complete Guide to Cats And Carbohydrates

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Whether cats need carbs is a hot topic – especially in the pet food industry. Your cat’s wild ancestors were carnivores that lived off small prey such as birds and mice. Their natural diet was high in protein but contained tiny amounts of carbohydrates. This has led to debate about not only whether cats need carbs, but if they could actually be harmful.

While the short answer is no, the longer answer is that carbs play all sorts of important roles in your cat’s health. In this article, I’ll explain what carbohydrates are and how they impact your cat’s health from a veterinarian’s perspective. I’ll also myth-bust the common misconceptions surrounding cats and carbs.

What Are Carbohydrates?

Carbohydrates include foods like potatoes, grains, and legumes. Nopparat Promtha / Shutterstock

Before making decisions about your cat’s diet, it’s helpful to understand what carbohydrates are. From a chemical perspective, a carbohydrate is any compound that contains carbon, hydrogen, and oxygen. This includes sugars and starches (digestible carbohydrates), and fiber (indigestible carbohydrates). Examples of carbohydrates you might see listed on the ingredients of your cat’s food include potatoes, grains, and legumes such as lentils, peas, and beans.

Digestible carbohydrates are broken down to make glucose, the main source of energy for every cell in the body. Indigestible carbohydrates cannot be digested, but still play an important role in gut health.

Can Cats Digest and Use Carbohydrates?

One of the common myths about cats and carbs is that cats cannot digest carbohydrates. There are three main arguments for this:

1. The natural diet of their ancestors was low in carbohydrates.
2. Cats have low levels of amylase in saliva and the small intestine, an enzyme involved in breaking down starch.
3. Cats lack glucokinase, a liver enzyme other mammals use to process glucose for energy, meaning they could struggle to metabolize it.

However, research shows that this is not the case. Multiple studies show that cats can digest carbohydrates as effectively as most other mammals – they just do it a bit differently.

While cats may lack some of the enzymes other species use to digest and metabolize carbohydrates, they upregulate other enzymes to compensate. This includes an enzyme called hexokinase, which – although less efficient than glucokinase – they have in much greater amounts than dogs.

They show other adaptations throughout their digestive tract and metabolism. As a result of these adaptations, an extensive scientific paper “Cats and Carbohydrates: The Carnivore Fantasy?” concluded that “cats can digest carbohydrates and absorb and utilize glucose in a manner similar to other species”.

Processing of Carbohydrates in Cat Food

When debating the digestibility of carbohydrates in cats, it’s important to remember that most cats aren’t given carbohydrates in raw forms. Carbohydrates are processed (usually ground and cooked) in commercial cat foods to improve digestibility.

A study examining the effect of carbohydrate sources on diet digestibility in cats found starch digestibility was over 93%. Other studies have found similar results, showing that cats can efficiently digest carbohydrates when they are properly processed.

So, the evidence shows that as well as being physiologically adapted to digest and metabolize carbohydrates, the carbohydrates found in commercial diets are processed to be highly digestible for cats. But are they just cheap fillers? Read on to find out if carbohydrates have any benefits for your cat.

Do Cats Need Carbohydrates in Their Diet?

The diet of a domestic cat is a lot high in carbohydrates than their wild ancestors. Kirsten McCarthy / cats.com

We know cats can effectively digest and metabolize carbohydrates in their diet, but do they actually need them? Strictly speaking, the answer is no. Carbohydrates are not an essential nutrient for most mammals, other than during certain lifestyle stages such as growth and reproduction. But carbohydrates are broken down in the body into glucose, which is vital. Glucose is the main source of energy for nearly every cell in the body. It is vital for your cat’s health, especially their brain.

Also Read: The 7 Best High Protein Low Carb Canned Cat Foods

Like other mammals, cats can gain glucose from three sources: fat, protein, and carbohydrates. Wild cats used protein as their main source of glucose. But we know that domestic cats can vary their energy source depending on their diet – and this may even be beneficial.

What Are the Health Benefits of Carbohydrates for Cats?

The main role of digestible carbohydrates is as an energy source. While cats can use protein as their primary energy source – like their wild ancestors – research has shown that using carbohydrates may be more beneficial.

A 2008 study looking at the effect of high-carbohydrate, low-protein diets in cats found a ‘protein sparing effect’. This means that when your cat is fed a high-carb diet, they adapt to use carbohydrates as their main energy source, meaning that the protein in their diet is available to be used for more important roles, such as:

• Metabolic processes in the body
• Building and maintaining muscle
• Healthy hair and skin

So, not only do carbohydrates provide an excellent source of energy for your cat, they also allow them to utilize the protein in their diet more effectively. But the benefits of carbohydrates don’t stop there.

Indigestible Carbohydrates

Hang on a second, haven’t we just established that cats can digest carbohydrates? Well, yes. But it’s a little bit more complicated.

Most of the debate around cats and carbs is about the group of carbohydrates called ‘digestible carbohydrates’. The research on this is clear: cats can digest these carbohydrates just as well as most other animals.

However, another large group of carbohydrates is indigestible carbohydrates – or fiber. Examples are cellulose, beet pulp, and pectin. Dietary fibers pass through your cat’s digestive tract without being digested or absorbed and don’t provide any energy. However, they offer a whole host of other benefits:

• Boost gut health: fiber is a prebiotic, meaning it provides a food source for the healthy bacteria in your cat’s gut, helping your cat’s microbiome to thrive!
• Regulate stool consistency: fiber absorbs water from your cat’s poop if they have diarrhea and adds moisture and bulk if they have constipation.
• Regulate gut motility: fiber regulates the movement within your cat’s gut, meaning it moves through the intestine at a healthy rate. This helps cats who suffer from constipation or diarrhea. It also allows your cat to absorb nutrients and eliminate waste products from their food easily.
• Reduce calorie density in food for overweight cats: slowly fermentable fiber (such as cellulose) adds bulk to food, meaning your cat feels full while eating fewer calories. These types of diets may be beneficial to your cat if they’re struggling to lose weight.
• Reduce hairballs: high levels of fiber can help hair to pass more easily through your cat’s intestinal tract, reducing hairballs.

Because of their impact on your cat’s gut, there is a growing interest in the role of high-fiber diets for cats suffering from gastrointestinal issues such as diarrhea, constipation, and inflammatory bowel disease (IBD).

Can Carbohydrates Be Harmful to Cats?

There is very little evidence that carbohydrates can be harmful to cats when fed as part of a nutritionally balanced diet. Rido / Shutterstock

When fed to cats as part of a nutritionally balanced diet, there is very little evidence that carbohydrates can be harmful. But you may have heard concerns that high-carbohydrate diets may cause obesity and diabetes. Let’s delve into why this is a myth.

Do Carbohydrates Cause Obesity in Cats?

Obesity is one of the biggest health concerns for domestic cats. Like us, cats become overweight when they eat more calories than they use. The remaining energy is converted into fat. As carbohydrates are an excellent energy source, you might worry that a high-carbohydrate diet could make your cat more prone to gaining weight.

But the opposite is true. Cats can gain energy from protein, fat, or carbohydrates. Diets high in carbohydrates tend to be low in fat, and vice versa.

A study looked at the influence of diet on fat in cats. They showed that a low-carbohydrate diet (and therefore high fat) can cause animals to gain 2.5 times more fat compared to high-carbohydrate (and consequently low fat) diets! Cats also prefer the taste of low-carbohydrate, high-fat diets so are more likely to over-eat.

Overall, the evidence shows that a high-carbohydrate diet could actually protect your cat from obesity. But, the amount you feed is much more important. Research shows that the major cause of obesity in cats is overfeeding.

Can Carbohydrates Cause Diabetes in Cats?

You may have heard claims that high-carbohydrate diets may increase your cat’s risk of developing diabetes mellitus. This is because of concerns around carbohydrates increasing the risk of obesity, as well as affecting glucose and insulin sensitivity.

Research does not support this theory. When healthy cats are fed high-carbohydrate diets similar to commercial diets, multiple studies have confirmed no adverse effects on blood glucose or insulin sensitivity.

However, while carbs don’t cause diabetes, a low-carb diet is usually the best option for cats that are already diabetic. According to the ISFM Consensus Guidelines on the Practical Management of Diabetes Mellitus in Cats, low-carbohydrate, high-protein diets are associated with better glucose control and a higher chance of remission. This is because diabetic cats are less able to regulate their glucose from carbohydrates than healthy cats.

How Much Carbohydrate Should Be in My Cat’s Food?

We’ve established that carbohydrates are not harmful to cats, but offer many benefits. But what levels of carbs should you be looking for in your cat’s diet?

The American Association of Feed Control Officials (AAFCO) sets minimum recommended amounts of protein (26% ME), fat (9% ME), and vitamins and minerals (totaling around 5%). This makes up 40% of the diet. Dry food typically contains at least 15% moisture, bringing the total to 55% – wet food contains even more water.

There are currently no minimum requirements for carbohydrates in cats (or other animals). But if you feed a complete and nutritionally balanced diet, carbohydrates will not exceed 45% ME, with an average of around 25%.

The most important thing is to choose a diet that is balanced and complete for your cat’s life stage and health. Rather than worrying about carbohydrates in your cat’s diet, concentrate on how much you are feeding. Overfeeding is the biggest risk for your cat becoming overweight or obese – which can shorten their lifespan and risk of a range of health conditions.