Rule 1: Amount and Quality of Carbohydrates

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.