What is the definition of glycemic index?
The glycemic index, or GI, is a ranking of different foods, according to how high they raise blood sugar levels after they are eaten. The foods are indexed from 0 to 100. Today, most pet food companies assumed it was the same for animals and usually converted the glycemic index for pets when formulating food.
Low glycemic foods are digested slower than high glycemic foods, and the nutrients take longer to be absorbed by the body. This slow digestion means that an animal eating low glycemic carbohydrates will feel fuller for longer. This is an obvious advantage for weight loss. Low glycemic pet foods use peas, lentils, barley, alfalfa and even apples as their source of carbohydrates. These carbohydrates are absorbed slowly by the digestive system, and only score half as high on the GI.
Since blood sugar levels rise slowly, there is little or no “crash” associated with high glycemic foods, mostly simply carbs. This eliminates things like fatigue, muscle weakness, and sometimes even aggression. This is an advantage especially for the diabetic animal.
In general, high glycemic foods tend to be carbohydrates; for example, dried kibble is high in carbohydrates and, hence, high glycemic. The canned varieties are low carbohydrate.
However, a food can be high glycemic, yet healthy. Examples are rice and potatoes, often a staple of pet foods. They do score high on the GI, but they are seen as highly nutritious items, to be avoided only if the animal has a problem. However, the Glycemic Research Institute of Washington D.C. maintains a website that posts dog foods certified to be low glycemic.
Just as with people, more and more pets are overweight and suffering from diabetes. Many pets also experience arthritis and other inflammatory diseases; research has shown time and again that inflammation is caused by high glycemic foods. Corn and wheat are something both obese and diabetic animals should avoid and, unfortunately, these are often items in pet food, especially the lower-quality store brands. You need to read labels carefully, therefore.
The best thing to do is consult with your veterinarian.