Remember those 9 Lives commercials back in the 1970s featuring a big orange tabby named Morris the Cat? Morris was a notoriously finicky cat who turned up his nose at all kinds of tempting foods…except 9 Lives cat food, of course.

Why exactly are cats such fussy eaters? According to a new British and Australian study, while cats may be drawn to food that tastes and smells good to them, they also instinctively choose foods with the optimal protein to fat ratio.

Scientists gave 50 domestic cats meals that were flavored with fish (positive), rabbit (neutral), and orange (negative). Researchers varied the protein to fat ratio in the differently flavored foods over the course of the study. As expected, the cats preferred the flavor of the fish, followed by the rabbit, and disliked the orange.

Despite their flavor preferences, overall the cats seemed to consistently self-regulate their protein to fat intake to the appropriate levels for a good feline diet. The cats naturally consumed 31-32 g protein and 13-14 g fat across 3 control groups.

Not surprisingly, cats prefer fish flavored foods that are high in protein. But left to their own devices, they will choose to eat foods that contain the right amounts of nutrients as opposed to choosing things that simply taste good.

So if your cat is a finicky eater, chances are it’s more about nutrition than just taste. Be sure to choose a high-quality, well-balanced commercial cat food for your favorite feline!