Compared to rice, barley is a better source of carbohydrates in the diet because of its low glycemic index that helps maintain stable blood sugar levels. (dogfoodchat.com)
Consequently, reducing carbohydrates in the diet makes insulin levels go down. (alivebynature.com)
Cats do not have a biological requirement for carbohydrate in their diet so these sources are likely included for their dietary fiber and nutritional value. (kittycatter.com)