It is important to do research when choosing the best lower-calorie or weight loss cat food because calorie contents vary, according to a study summarized in an article on readingeagle.com.
Researchers evaluated 49 cat foods designed to aid in weight management. Their findings, published in the Journal of the American Veterinary Medical Association, showed that dry food calorie contents varied from 235 to 480 calories per cup, while canned food varied from 78 to 172 calories per cup. The researchers recommended that consumers check with manufacturers for the actual calorie content of the petfood. In addition, the article says that a normal cat requires 20 calories per pound of ideal body weight per day, but that overweight cats should only be given about 50% to 70% of that amount.