A controversial and well debated topic in feline medicine is whether dietary carbohydrates are an essential component of your cat’s diet, cats are truly carnivorous mammals after all. This article aims to explore and critically review this topic to provide a better understanding of cats and carbs!

What are carbohydrates?

I won’t dive too far into the complicated science but carbohydrates, also known as macronutrients are molecules composed of carbon, hydrogen and oxygen and they make up simple and complex sugars. ‘Dietary carbohydrates’ refer to those which are digestible, primarily simple sugars (including glucose) and starches (Verbrugghe and Hesta, 2017). In commercial pet foods, starches and complex carbohydrates make up the majority of the carbohydrates (Laflamme et al, 2022).

 Some people think of carbohydrates as being just ‘fillers’ in cat food. What does this actually mean? ‘Fillers’ are thought of as ingredients with little nutritional value that bulk feeds. Sources of carbohydrates in commercial cat foods include potatoes, cereals, grains and rice, all of which encompass some nutritional value. 

The big debate

A quick google search will bring up a lot of controversy into this topic. 

Is it safe for my cat to eat carbohydrates? 

The bottom line answer is yes.

We know that cats are true carnivores and in the wild they hunt prey. Mammalian prey species are high in protein, moderate in fat and minimal carbohydrates (Verbrugghe and Hesta, 2017). The evolutionary background of felines is what has led to speculations and debates as to whether or not cats even need carbohydrates in their diet? These poorly evidenced speculations include cats being poor at digesting carbohydrates and high-carbohydrate diets being detrimental to their health (Verbrugghe and Hesta, 2017). Recent scientific evidence disputes these speculations. So, let’s explore this further.

Firstly, ‘essential nutrients’ are defined as those needed by the body which either cannot be made by the body or are made in insufficient amounts (Laflamme et al, 2022). 

Like all mammals, cats have an essential need for glucose, a simple sugar made from carbohydrates

Glucose is required by the brain, nervous tissues, red blood cells and other tissues (Eisert, 2011). So this is perhaps where the speculations come from. Adult cats, however, do not have specific known dietary requirements for carbohydrates, which they make in their livers (gluconeogenesis). However, they do have a requirement for energy, which they obtain from protein, fats AND carbohydrates. Carbohydrates have always been considered as a non-essential nutrient for dogs and in particular cats but the presence of carbohydrates in their diet ensures proper metabolic feeding balance (Agar, 2001). 

The term non-essential is frequently incorrectly interpreted as ‘should not be fed.’ 

There have been discussions that high-carbohydrate diets may contribute to the development of serious health conditions such as diabetes and obesity. But, there is absolutely no evidence to support this idea. Of course too much of any diet has the potential to lead to obesity and we know that obesity is a significant risk factor for feline diabetes. 

Additionally, it is advised that cats with diabetes are fed low carbohydrate diets to allow them to achieve better glycaemic control (Laflamme, 2010). In diabetic patients, there is an ultimate aim to maintain the glucose level in the blood within a safe and acceptable level. Therefore, it makes sense to want to manage their dietary carbohydrate intake as this will help with glucose regulation. This does not mean that feeding a diet rich in carbohydrates is going to result in your cat developing diabetes and there is no pattern proving otherwise. 

How much do they require?

Alternate to other food components such as protein, there is no specific desired minimum carbohydrate amount stated in any literature, this value is simply unknown. Many pet food packaging fails to contain details on carbohydrate content but the majority of the carbohydrates is predominantly broken down to starch. Whilst being a non-essential nutrient, cats are still perfectly capable of digesting and utilising dietary starch (Domingues, 2008).

Furthermore, the carbohydrate content can be worked out relatively easily by deducting all other percentages from one hundred and calculating the remaining amount, this may result in some degree of inaccuracy. There is no denying that the amount of carbohydrates in diets should be included in pet food formulas. 

Furthermore, I reviewed my own cat’s purina dry food and it has a carbohydrate content of 22%, whilst the wet food alternative contains a much lower value. The specific amount of daily carbohydrates your cat should receive still remains elusive.

To conclude, carbohydrates aren’t just empty fillers in cat food

They are “fillers” (in that they are not essential) but they are not empty and your cats can and should eat carbohydrates. Controversy still surrounds the inclusion of carbohydrates in cat food; however, the scientific evidence now available thanks to the advancement of Veterinary medicine does support feeding carbohydrates until proven otherwise. Please speak to your Vet to discuss your cat’s nutritional needs further.