It is well recorded that cats have no nutritional requirement for carbohydrates, their energy source of glucose is derived from protein through a process of gluconeogenesis, even in protein deficient diets cats are unable to downregulate this function. Wild felid diets are very low in carbohydrates and in studies where cats are allowed to self-select, they choose low carbohydrate diets. Amylase is produced in the pancreas but at lower amounts than seen in most other animals, showing that they have evolved to consume a high protein diet to source their energy.
But what can carbohydrates do in the feline body?
There is a hypothesis that suggests that a high carbohydrate content in the feline diet will put stress on the pancreas to produce insulin, over time there can be endocrine ‘burn out’ resulting in the development of Diabetes Mellitus.
High carbohydrate diets contribute to excessive weight gain from the pancreas producing large amounts of insulin thus causing the body to store fat in reserve.
High carbohydrates are often needed to form extruded feed ie Kibble, a cat fed a high amount of dry food can easily be in a state of dehydration due to their lack of thirst drive this in turn can directly affect urinary tract and kidney health when urine is highly concentrated due to a lack of moisture, thus for optimal cellular hydration and reduction in urine concentration a high moisture diet should be consumed, these are usually lower in carbohydrates and higher in meat protein.
Rice has been shown to directly affect Taurine availability in diets that have rice bran or whole rice in the formulation. Taurine is a vital sulphur amino acid that is essential to cats and supports healthy heart and eyes.
In a study conducted on dogs carbohydrates have been shown to reduce the diversity of beneficial gut microbes and high meat diets improve the diversity. A gastrointestinal tract with a poor diversity on microbes can have systemic effects on how the body functions such as weakened immune function, poor nutrient production such as some of the B vitamins and vitamin K that are produced by gut bacteria, and is thought to be a factor in IDB in cats.
In conclusion when we look at the potential negative effects carbohydrates can have on the feline body it is clear that we should aim to be feeding a high meat low carbohydrate diet for optimal health.
References:
1. The Carnivore Fantasy? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5753635/
2. The Effect of Feeding Inversely Proportional Amounts of Dry Versus Canned Food on Water Consumption, Hydration and Urinary Parameters in Cats https://www.vin.com/apputil/content/defaultadv1.aspx?id=7054968&pid=12886
3. Environmental Risk Factors for Diabetes Mellitus in Cats https://onlinelibrary.wiley.com/doi/full/10.1111/jvim.14618
4. Focusing on Feline hydration https://veterinary-practice.com/article/focusing-on-feline-hydration
5. Dietary Rice Bran Decreases Plasma and Whole-Blood Taurine in Cats- https://academic.oup.com/jn/article/132/6/1745S/4687888
6. Key bacterial families- (Clostridiaceae, Erysipelotrichaceae and Bacteroidaceae) are related to the digestion of protein and energy in dogs https://peerj.com/articles/3019/
Your Cat’s Diet and Chronic Inflammation- https://www.animalbiome.com/blog/how-your-cats-diet-could-lead-to-chronic-inflammation-and-steps-you-can-take-to-prevent-it