My cat became seriously overweight in a multi-cat household. I need advice on weight loss in cats.


I have a young adult cat that became obese when I lived in a multi-cat household. Now we are in our own place with a cat that weighs 25#, if not more! Right now he's eating a grocery store indoor formula, but I would like to put him on a weight-loss food for a while. I started researching and found sites with horror stories about cat foods and even came across one that said that indoor cats shouldn't be given dry food. I have a limited income but I love my cat--I'm TIRED of giving him the food with all the junk in it. I am suspicious of the supposedly better brands of food. Should I change him to canned? Any brand suggestions for either?


I am glad to hear that you are trying to help your cat lose weight as obesity in cats is a serious problem that can lead to diabetes or musculoskeletal problems (such as arthritis).   I would definitely recommend that you discuss your cat’s weight with your local veterinarian.   A thorough physical examination and lab work may be helpful in determining if your cat has any additional health problems, and your veterinarian will likely have additional recommendations regarding weight loss.

The most recent research for cats does indicate that cats are more likely to lose weight and maintain a healthy weight on a high protein and low carbohydrate diet (the “Catkins” diet).   The body composition of a mouse is approximately 45-52% protein, 40-45% fat, and 3-5% carbohydrates so a high protein, high fat, and low carbohydrate diet is more similar to a cat’s natural diet.    Most dry cat foods contain much higher levels of carbohydrates so feeding an all canned food is a good way to reduce carbohydrate consumption.     

As you have found, there is a lot of conflicting nutritional information available on the internet regarding brands of cat food.   You do not have to buy an expensive food to be certain that your cat is getting adequate nutrition.   You should check the label to be certain that the diet meets AAFCO (Association of American Feed Control Officials) requirements for an adult cat and look for diets that contain less than 10% carbohydrates.  

Even if you are feeding a low carbohydrate diet, you will need to limit the overall calorie intake for your cat.   The low carbohydrate diets are higher in fat and therefore more calorie dense.   If you can determine how many calories your cat is currently eating, you can start by reducing his calorie intake to 80% of the current amount.   If you do not know how many calories that he is ingesting, you can start by feeding approximately 330-350 kilocalories per day (based on your estimate that he currently weighs 25 pounds).   You will need to weigh your cat on a weekly basis; we would like to see a weight loss of approximately 1% of his body weight each week.   The amount of calories that he is being fed may need to be adjusted based on his response.    We do not want to see an excessively rapid weight loss as this can also cause health problems such as fatty liver syndrome.   Be certain to transition to the new diet gradually (over 7-10 days) to avoid causing any gastrointestinal upset.

Increasing your cat’s activity level will also help to facilitate weight loss.   You can try playing laser tag or using other interactive toys to try to increase his activity level.