Surprising studies:
Dogs eat fat, cats prefer carbs


Whether you’re a dog or cat person, it’s easy to agree that Australia’s most loved pets are wildly different in disposition, nature and behaviour.

Now, a surprising new study has determined that dogs prefer high fat foods, whereas cats pounce on carbohydrates.

The study, published in the Journal of Experimental Biology, helps shed new light on the common theory that cats need a high protein diet.

These findings also highlight new concepts about optimal nutrition for our furry friends.


“The numbers were much different than what traditional thinking would have expected,” explained Professor Jean Hall, from the Carlson College of Veterinary Medicine at Oregon State University.

“Some experts have thought cats need diets that are 40 – 50% protein. Our findings are quite different than the numbers used in marketing and are going to really change the pet food industry.”


Balancing palatability the key to new findings


Hall’s research team monitored 17 healthy adult dogs and 27 cats, over 28 days.

The animals were offered four different tasty treats, allowing macronutrient choices based on the animal’s instinctive preference.

“Previous studies have shown that if you don’t balance palatability between foods, cats do in fact prefer to eat very high levels of protein – and dogs want to eat a lot of fat,” said Hall.

“When you balance palatability, both dogs and cats prefer significantly different macronutrient content than what they would choose based on taste.”

The animals could choose from high-fat, high-carbohydrate, high-protein or nutritionally balanced foods.
The study found that cats, on average, chose to get 43% of their calories from carbohydrates and 30% from protein.
In contrast, dogs selected 41% of fat and 36 per cent of carbohydrates.

Interestingly, not a single dog or cat in the study chose to consume the highest number of calories in protein.


Findings identify age and body mass as key factors

The cats’ choice also seemed to correlate with age and body mass – with younger, leaner cats tending to select protein-rich foods.

Meantime, high-protein foods were least popular among younger dogs with less body fat.

“Because the choice of macronutrients was influenced in both dogs and cats by age and either lean body mass or fat body mass, that suggests a physiological bias for what they chose to eat,” said Hall.

Researchers believe this information will inform the production of new pet food products and differentiates substantially from commonly held views about optimal diets for dogs and cats.