Because cats are true carnivores, in that they’d only eat meat in the wild, they usually do very well with high-protein diets regardless of the goal. When it comes to weight loss, higher protein can help preserve muscle mass as cats drop weight,” notes Dr. Ushi-Phillips. “Not only is muscle important for a healthy cat, but muscle is also more metabolically active and requires more calories to maintain. That means more muscle can increase a cat’s base calorie requirements and make it easier to achieve a weight-reducing caloric deficit.