Research overview: the feline sweet taste deficit and loss of the sugar receptor

Cats are indifferent to sweetness, and this overview reviews the genetic basis. A defect in a gene encoding part of the sweet taste receptor leaves cats unable to taste sugars, consistent with a carnivorous diet in which detecting sweetness offers little benefit. This loss is shared across the cat family. Researchers identified it through molecular genetics and taste testing. Why it matters: the sweet-taste deficit is a vivid molecular fingerprint of obligate carnivory, showing how the sensory system, like the metabolism, has shed capacities irrelevant to a meat eater. It explains the everyday observation that cats ignore sweet foods, and it exemplifies how dietary specialisation reaches all the way down to the genes governing taste, aligning what a cat can perceive with what it actually eats.