Overweight Cats: Diets and Associated Health Risks

WebMD discusses health problems common in overweight cats, and offers tips on helping your cat to trim up.

Medically Reviewed by Elizabeth A. Martinez, DVM on July 05, 2009
5 min read

Bea Sacks of Huntington Woods, Mich., calls Jack, her adult cat, “big.” But she has no idea how much he weighs or whether a diet is in order. That’s because Jack, like many housecats, eats whenever he wants and rarely visits the veterinarian. Unfortunately, if Jack is even a pound over his ideal weight, he could be in trouble. Overweight cats are far more likely to develop osteoarthritis, type 2 diabetes mellitus, respiratory problems, and non-allergic skin conditions.

If you can hear a thud when they jump off the bed, you should consider putting your cat on a therapeutic cat diet, modifying your feeding habits, and getting them to move more. It’s a good idea to see a veterinarian first to rule out other issues. Plus, the vet can help you formulate a sensible weight-loss and exercise plan. What the vet can’t do is restrain your urge to reward your cat with treats or to give in to their mewling when you change their diet. Keep in mind: a slimmer, fitter cat is a happier and longer-lived cat.

An average domestic shorthair should weigh between 8 and 10 pounds, and although you can attempt to put Tiger on a scale, there are other ways to check their fitness:

  • Gently squeeze the sides of your cat’s rib cage. If you can easily feel the ribs, they are probably not overweight. If you have to press to get at the ribs, they may be heavier than they should be.
  • Look at your cat’s waistline. Their body should become more slender from the belly to hindquarters.
  • A swinging pouch between your cat’s hind legs is an indication your cat is overweight.

The primary responsibility that you, the caretaker, have is to limit the calories your cat is getting. A 10-pound indoor cat should take in about 200 calories a day, according to the Association for Pet Obesity Prevention.

Here are some of the basics in limiting calories and slimming down your cat:

  • Measure out food. Divide the cat’s targeted calorie intake into four to six small meals.
  • Keep their water bowl full.
  • Leave out cat food for a limited amount of time.
  • Set a weight loss goal with your veterinarian.
  • Avoid giving treats, or if you must, use a few pieces of their dry food as a substitute.
  • Don’t share human food with your cat; it’s fattening and can cause diarrhea.
  • Don’t allow your cat access to dog food.

The consensus among vets is to implement a new diet slowly. Cats may stop eating if you suddenly confront them with different food.

“The bottom line is, you have to cut calories in proportion to the amount of work the cat is doing,” says Johnny Hoskins, DVM, PhD, DACVIM, of Branson, Mo. “We try to do it over a several-month time period.” The Association for Pet Obesity Prevention says a loss of about 1 pound per month is healthy.

Research has shown that there are several ways of approaching a cat diet. Fortunately, there are many commercial varieties of therapeutic canned and dry foods that are palatable and nutritionally sound. Hoskins tells WebMD that it’s fine to combine canned and dry foods for your cat’s diet.

Joe Wakshlag, DVM, PhD, DACVN, is a clinical nutritionist with Cornell University’s College of Veterinary Medicine. He recommends a diet of low-calorie canned food because it has more fillers than dry food. The recommendation is not aimed at your cat, but at you. The canned food tends to make you, the caretaker, feel you are giving your cat enough to eat. Wakshlag also says to make sure you don’t forget to look at the calorie count on the label. “I think the bottom line is you have to replace fat with protein and carbohydrates,” he tells WebMD. “The key is to remove fat, which is contributing the most calories.”

The latest trend in feline weight loss management is a high-protein/low-carb diet, the so-called “Catkins” diet. Hoskins says he prefers low-carb cat diets because he believes carbohydrates raise the risk of diabetes. Diets that contain L-carnitine help maintain lean body mass, he says.

Other research has shown that obese cats lose weight without losing lean body mass following low fat/high fiber diets and high fat/low carb diets. Both kinds of diets have been shown to improve glucose tolerance.

Look at the label on the cat food to make sure your cat is going to get the right nutrients for their stage in life and that the top ingredients are meat, meat byproducts, or seafood. Nutrients like taurine and B vitamins are also good.

Keep in mind: cats are natural carnivores, so vegetarian diets won’t do.

In a word, no. A good cat food contains all the vitamins and minerals your cat needs. Do not use supplements unless directed to do so by your veterinarian.

If the diet isn’t working, your cat is probably still eating too much. Retaining weight is usually not related to medical problems, Hoskins says. “No disease is contributory to obesity” in cats.

Wakshlag adds that endocrine disorders like diabetes and hyperthyroidism don’t cause obesity in cats.

Motivating Nibs to move for reasons other than food is one of a cat caretaker’s bigger challenges, especially if the cat doesn’t venture outdoors. But veterinarians agree that laser pointers, which emit a pinpoint of light that intrigues cats and often gets them off the couch, are good for owners who don’t want to move much themselves.

Other interactive toys, like sticks with feathers at the end and balls, are fine, too. Climbing apparatus and scratching posts may also interest your cat, as will empty boxes.

Hoskins says that cat owners should encourage physical activity from the start, when your cat is still a kitten. He tells WebMD, “One of the problems in reversing obesity is that you can change their diet, but it’s hard to do anything with their activity.”