It is ironic that about 31% of dry cat food is carbohydrates. It has to be in order to make the stuff. And I think it is correct to say that carbohydrates taste sweet to at least some degree. Therefore, I’ve got to conclude that domestic cats do not taste the sweetness in dry cat food or perhaps it is been drowned out completely by the artificial tastes that they add to the food to make it palatable, even addictive, to domestic cats.
It’s ironic because it is true that cats can’t taste sweetness. This must be an evolutionary consequence. Everybody by now knows that cats are obligate carnivores i.e. they need to eat flesh and pretty well nothing else (although they will eat some plant material in the digestive tract of the prey that they eat).
The science of why they don’t have sweet receptors (in their tongues?) is complicated but cats can’t taste sweetness so say the scientists. And it appears that they are unique in this regard because other carnivores can to a certain extent taste sweetness.
Cats don’t have the amino acids that make up the DNA that creates a gene which in turn creates the proteins which in turn are part of the process which sends a signal to the brain indicating to the animal that they have chomped down on something sweet. And herbivores need to know that because carbohydrates are a rich source of food for plant-eaters. That is the science in layman’s terms for how and why animals detect sweetness. And as stated cats can’t do it because they don’t have to do it because their bodies are tailor-made to live off the flesh of animals with a touch of vegetation.
It’s more complicated than that but I know people don’t want to read complicated scientific stuff because it put you off. There’s been quite a lot of research on the subject and you can go back to 2005 to find early studies which provide evidence that cats do not have a preference for sweetened water over regular water. This identified their lack of sweetness receptors.
Although anecdotal evidence points to cats detecting sweetness because they eat ice cream, for example. But this is because they like the fat in milk not the sweetness in the ice cream. Despite the fact that cats can’t taste sweetness they can taste things that we can’t such as adenosine triphosphate (ATP). This is a compound that supplies the energy in every living cell and which is a signal for meat. In other words cats can detect a substance which tells them that they are eating meat.
It is suggested that one reason why there is a unhealthily high proportion of domestic cats getting is diabetes because of the convenience of dry cat food which is high in carbohydrates which the domestic cat is not designed to eat. It keeps them in a mild hypoglycaemic state, it is said, and their metabolism is messed up by the high carbohydrate content, overburdening the pancreas which produces insulin resulting in a steady decline into sugar diabetes – high blood sugar levels which damages some organs.