Dogs prefer to eat fat, and cats surprisingly tend toward carbs.

Dogs prefer to eat fat, and cats surprisingly tend toward carbs.Dogs gravitate toward high-fat food, but cats pounce on carbohydrates with even greater enthusiasm, according to research into the dietary habits of America's two most popular pets. The study sheds new light on optimal nutrition for the animals and refutes a common notion that cats want and need a protein-heavy regimen.Findings were published this month in the Journal of Experimental Biology. "The numbers were much different than what traditional thinking would have expected," said the study's corresponding author, Jean Hall, a professor in the Carlson College of Veterinary Medicine at Oregon State University. "Some experts have thought cats need diets that are 40 or 50 percent protein. Our findings are quite different than the numbers used in marketing and are going to really challenge the pet food industry." Dietary proteins contribute to a number of important physiological functions such as blood clotting, production of hormones and enzymes, vision and cell repair. Protein also has the most power to make the eater feel satiated; carbohydrates are No. 2 in that regard, followed by fat.