When we eat food, some of it dissolves in our saliva and comes in contact with the taste receptors.
Depending upon the flavour, a particular taste receptor activates and sends information to an area in the brain (gustatory cortex) that identifies the taste.
The sweet receptor is made up of two proteins generated by two separate genes —Tas1r2 and Tas1r3.
Though cats’ taste buds are similar to those of humans, Tas1r2 is kind of broken.
So, the proteins to make the sweet receptor function can’t be made.
There is still no conclusive theory on why Tas1r2 in cats (and lions, tigers, etc.) is broken.
But experts say it could be because cats are obligate carnivores, i.e., they must eat animal products to survive.
And they don’t need carbohydrates in their diets.
So, their taste buds may have evolved to accommodate their dietary needs — no need to detect sweet tastes.
The cat family is the only one that can’t taste sweetness among all the mammals examined so far.
Cat owners may claim that their beloved pets love ice cream and doughnuts, but it’s the fat that cats enjoy.
