Carbohydrates are a controversial component of a cat’s diet. Cats are obligate carnivores, and their natural diet in the wild contains minimal carbohydrates, around 5% from chewing grass and consuming the stomach contents of their prey. However, dry cat foods often contain higher levels of carbohydrates from various sources.

Classification of Carbohydrate Sources #

Carbohydrate sources in dry cat foods are classified into three groups based on their quality and digestibility for cats:

Group C: Corn, wheat, barley

• These grains are popular fillers and inexpensive sources of carbohydrates, vitamins, and minerals.
• However, their digestibility for cats is relatively low, and they can cause food intolerances and allergies.

Group R: Rice, oatmeal, sorghum (millet)

• These ingredients are also common fillers and sources of carbohydrates, vitamins, and minerals.
• The digestibility of carbohydrates from these sources is higher than that of grains like corn or wheat.

Group P: Potatoes, peas, chickpeas, lentils, tapioca

• These vegetables, legumes, and tubers are excellent non-grain sources of highly digestible carbohydrates, vitamins, minerals, and fiber (like peas and chickpeas).
• They also contribute some plant-based protein (8-20% dry matter protein) to the overall protein content of the food, although this is not explicitly declared.

Combination Factors for Different Carbohydrate Groups #

Since dry cat foods often contain multiple sources of carbohydrates, combination factors are used to account for the varying quality of the carbohydrate sources present. These factors range from -1.000 (lowest quality) to -0.700 (highest quality):

• Combination C (corn): -1.000
• Combination CR (corn and rice): -0.950
• Combination CP (corn and potato): -0.925
• Combination RC (rice and corn): -0.875
• Combination R (rice): -0.825
• Combination RP (rice and potato): -0.800
• Combination PC (potato and corn): -0.775
• Combination PR (potato and rice): -0.725
• Combination P (potato): -0.700

The combination is determined by the order of the carbohydrate sources listed in the ingredients, with a maximum of two groups considered.

Calculation of Points Deduction #

The baseline for carbohydrate content is 5% dry matter. Based on the carbohydrate combination factor, points are deducted for every 1% of carbohydrates above this level.

Points deducted = (Total dry matter carbohydrates – 5) × Carbohydrate combination factor

For example, if a food contains 38% carbohydrates with a combination CR (corn and rice), the points deducted would be:

(38 – 5) × (-0.950) = -31 points

Importance of Minimizing Carbohydrates in a Cat’s Diet #

As obligate carnivores, cats cannot digest and utilize carbohydrates efficiently. Their natural diet consists primarily of animal-based proteins and fats, with minimal carbohydrate intake. Excessive carbohydrate consumption can lead to various health issues in cats, such as:

• Obesity and weight management problems
• Diabetes and insulin resistance
• Digestive issues and malnutrition
• Allergies and food intolerances

Dry cat foods can better align with a cat’s natural dietary requirements and promote overall health and well-being by minimizing carbohydrates and favoring high-quality, digestible sources like potatoes, peas, and lentils.