Dog and cat health care topics, videos, and articles

Dog and puppy health care questions and answers, articles, videos and images

Obesity In Cats... How It Occurs and How To Prevent It

We surely do live in the "land of plenty".  Many of us and our dogs and cats are not simply overweight but fit the description of being obese.  Too many calories are ingested for the amount of energy expended through physical activity.  No longer do we or our pet dogs and cats have to track down and capture our meals.  Evolution never prepared us for consistent, easily acquired food sources.

Kitten and cat health care questions and answers, articles, videos and images

View all topics

If your pet is sick, call your local veterinarian immediately

View all topics

 Obesity In Cats...
How It Occurs and How To Prevent It
by T. J. Dunn, DVM


We all know how cats crave mice and birds as a food source.  Did you know that a mouse or a bird is composed of only 3 to 8 percent carbohydrate and most of that is from what is in the digestive tract?  The rest is water, a few minerals, protein and fat.

There are more cats than dogs in the USA at this time.  And 40 percent of those cats are considered to be obese!  Only 5 to 10 percent of all cats can be classified as only slightly overweight.  In recent years Feline Diabetes Mellitus (diabetes) has become almost a daily diagnosis in animal hospitals all across America.  Our cats are at risk for a number of obesity related disorders.  Documented research indicates obese cats are far more prone than cats of Indoor cats are prone to being overfed.normal body weight to Diabetes, arthritis and a very serious disorder called Hepatic Lipidosis.  And the 40 percent obesity figure seems to be growing. 

So what is happening that predisposes our domestic felines to a life of sedentary obesity?  The answer is multifactorial but to simplify, just remember this… any individual mammal (dog, cat, horse, human, etc.) will gain body weight if it consumes more calories than it burns as fuel for energy.  That’s pretty simple, but true.  In Nature, food acquisition has never been a sure thing for any creature… not for canines, felines or humans. 

So food acquisition has always been accompanied by physical exertion to capture (or cultivate) and consume the food. It is only in recent times that the unnatural situation of food excess, readily acquired and consumed with little accompanying physical exertion, has become a way of life.  We humans have figured how not to have to do all that work of capturing and cultivating to build up stores of food.   Through agricultural expertise we have learned how to grow food and raise livestock and to have those food sources readily available and in abundance… just in case we get hungry!  We learned how to refrigerate, dry, preserve and store foods in large quantities that assured us we would not have to endure long and unsuccessful hunting forays nor suffer through famines.  We have created the very same food acquisition assurances for our domestic dogs and cats.  They, as we, no longer have to hunt to survive.  Indeed, we no longer even have to live outdoors.

It’s interesting that our pets have mirrored our own tendency to have trouble with weight control.  The major difference, though, is that we humans have complete control over what our pets eat and how much they eat.  Unless your dog or cat is sneaking into the fridge and making ham and cheese sandwiches late at night when no one is around, the only way they get to eat is when YOU place the food in front of them.

Every veterinarian has repeatedly heard a serious minded dog or cat owner state “I know you think she’s overweight, Doctor, but it isn’t from the food!  She hardly eats a thing.”  Well… is the pet overweight from high calorie air?   Maybe it’s the water… or from laying on that couch all the time.  That’s it!  The couch is making the kitty fat, not the food.

Seriously, far too many pet owners truly believe that food intake has nothing at all to do with their pet’s weight and no amount of counseling will convince them otherwise.  If that describes your position, read no further because the rest of this article is all about how to feed the proper food and in the correct quantity so that the cat will loose weight safely or maintain an optimum weight.  There will be nothing in this article about the effect of high calorie air, Many commercial cat foods actually predispose a cat to problems with weight control water or comfortable furniture on the cat’s weight problem.

Any cat that is overweight should have a physical exam performed, exact weight measured and blood and urine tests run.  It is vital that normal thyroid hormone levels are present and that the cat has no physical or metabolic dysfunction.  If the cat is physically normal, other than the abnormal body weight from fat deposition, then a gradual and careful weight loss program can be instituted.  First, let’s look at what the causes of obesity are and what we can do to correct OUR mistakes:

FREE CHOICE FEEDING1-800-PetMeds Fetch/125x125.gif
THE main reason for feline obesity (as well as obesity in other mammals) is the consumption of too much food.   Deny it all you want, it is a fact. 

   What we do…
Many cats are fed “free choice”, which means there is food available all the time and the cat eats whenever it wants.  (Pretty unnatural for a true carnivore that evolved as a hunting machine!)  Free choice feeding has probably been the biggest single factor contributing to feline obesity.

   What we should do…
Feed one or two small portions daily and control the amounts fed so that over a period of time the cat does not gain weight.  Many pet owners must downsize what they think is a “normal” portion.  A meal for a 175-pound human might weigh 16 to 24 ounces.  A seven-pound cat weighs 1/25 of the 175-pound human.  So a cat’s meal should proportionally be about 1/25 of a human meal.  That comes out to between 0.6 and 1.0 ounce of food per meal for a seven-pound cat… about the same weight as a mouse.  Cat owners must stop thinking in terms of “cups of food” and start thinking in terms of ounces of food.

Click on an image to view a larger version in a new window

obesity in cats Overweight cats are more prone to urinary tract infections Stray and outdoor cats seldom become overweight Surgery is more difficult in overweight pets
We love our pets and sometimes food becomes a form of bonding and care-giving The overweight cat can be predisposed to urinary tract infections Feral and stray cats seldom are obese The overweight or obese pet has greater risks during surgery.

From training sessions to bird feed to dog and cat supplies to pocket pets...

ID tags and thousands of other pet supplies including pet foods!
Amazing Amazon
1-800-PetMeds Pet Supplies Free Shipping $49
Huge selection of prescription and non-prescription medications for your pets

Cats, unlike most mammals, have no carbohydrate-digesting enzyme called Amylase in their saliva.  Humans and dogs do and actually begin the digestion of carbohydrate in the mouth.  In the intestine, amylase secreted from the pancreas breaks down large carbohydrate molecules into absorbable smaller units of glucose.  Cats have measurably less amylase activity than humans or dogs.   Nature did not intend the kitty to be a carbohydrate consumer.

   What we do…
We purchase convenient, attractively packaged and preserved dry foods mainlyLT - 031610 - 125x125 F&T because we can pour it in the bowl and forget it.  Dry pet food must have higher levels of flour and sugar than canned foods so that the kibble will stay uniform and not fall apart.  Spoiling doesn’t readily occur because of the preservatives so the kitty can eat whenever it wants and we don’t have to prepare cat meals very often.  Unfortunately, especially with dry diets, because of the metabolic biochemistry that converts the high carbohydrate content in almost all of today’s commercial cat foods into stored fat, the cat is really at risk for weight gain.

   What we should do…
Feed a diet consistent with the nature of a true carnivore… a meat based diet.  An ideal feline diet Control the portions and you'll control the weightwill have a high protein level in the 35 to 45 percent range on a dry matter basis (meaning the percent in the diet when the water has been removed) and moderate fat content with a low percentage of carbohydrate grains.  A multitude of research reports have proven that diets high in protein and fat are most beneficial for carnivores.  Cats cannot handle large carbohydrate loads efficiently.  After a meal rich in carbohydrate the feline’s blood level of glucose tends to stay higher than normal for long periods of time.  They become persistently hyperglycemic and this long term stimulus on the beta cells in the pancreas… the cells that produce insulin… renders those cells less sensitive to the blood glucose.  As a result less insulin is secreted to bring down the blood sugar level.  Nutritionists call this “down regulating’ of the beta cells; the insensitivity of the insulin secreting beta cells leads to what is termed “insulin resistance”.    This scenario is a prelude to diabetes.

   What we do…
And as sensitive and caring humans, we always want to reward our kitty by providing extra special treats.  Treats for cats have high levels of carbohydrate (flower and sugars) and lots of flavor enhancers to entice the cat to eat even when it is not hungry.  Cats that annoy us with vocalizing and pretending that they are starving to death sometimes are rewarded for that annoying vocalizing by being given a treat to “keep ‘em quiet”.  When we provide the treat we reinforce the vocalizing, effectively rewarding the cat for making all that racket, and essentially training the cat to make even more noise!

   What we should do…
Stop feeding treats to the overweight cat.  IF you think your cat NEEDS a treat, cut up little bits of fresh chicken or fish and feed as a natural protein treat… not a treat made from grains, food coloring, propylene glycol, and flavor enhancers.  And NEVER feed a treat as a means of stopping a cat from vocalizing because it has the exact opposite effect and actually reinforces the cat’s vocalizing/begging behavior.

   What we do…
Diabetes in cats is thought to be related to excess caloric intake.
Feeding the “Recommended ” daily portions indicated on pet food labels will nearly always result in feeding more calories than the animal needs for an average day’s energy requirements.  The carbohydrate excess, unneeded as fuel for metabolism or physical activity, gets converted to fat and stored in the cat’s fat reserves.  The odds are very high that if you feed the size and numbers of meals suggested on the pet food label’s feeding recommendations, the cat (or dog) will end up overweight.

   What we should do…
Tailor the amount fed to the cat’s body character and physical activity.  If the cat looks and feels overweight… it is!  You are feeding too much for that cat’s daily needs for energy for exercise or physical activity; and regardless of what the pet food label’s suggested amounts to feed are, you must feed less than that if the cat is to have a normal (healthy) body weigh.

   What we do…
We fill the bowls with food and water, clean the litter box,  and say “See ya later, Kitty, I’m off to work”.

OK… let’s say that you can’t help it.  You simply are not going to change the food amounts, kinds and portions you have always been feeding your overweight cat.  If you are to be successful in promoting weight loss in your cat you will have to increase its’ energy (calorie) burning activities.  This is much easier to do with a dog by taking it for a walk or run, throwing a ball, swimming, etc.  Good luck going for a run with your cat!  Most cats spend most of their time sleeping on the couch, are left alone for long periods of time and really have nothing happening in the home that would trigger a carnivorous hunter’s interest levels.  There is nothing to chase, nothing to hide from, and nothing to stalk and run down.  There is nothing else to do but to take cat naps!

   What we should do…
To assist in improving the kitty’s physical activity, you can add some interactive play toys to the cat’s environment.  Consider adopting a friendly and playful cat from the local shelter so the solitary cat has “someone” to interact and play with.  Many people believe two cats are more fun to have and more entertaining and no more trouble than a single cat.  You can also buy toys that simulate an escaping prey and that really interest the cat in play behaviors.  Cats can be exercised but you may need some imaginative toys and ideas to get the job done. 

Now that you know that the cat is a true carnivore and efficiently utilizes meat protein as a major component of the diet, you understand why a carbohydrate rich diet simply does not make sense for felines.  Cats are not plant-based grazers; they are hunters of other animals and to reach an optimum state of health they must comply with what nature programmed them to be.  There are no vegetarian diets for cats.  No matter what your own personal preference is regarding the ingestion of meat, by Nature’s own rules the cat requires meat in its diet.  One small aspect of this need for meat is the requirement for ingesting Vitamin B12 (Cyanocobalamin).

As the cat’s caretaker, you have complete control over what your cat eats, how much it eats and how often it eats.  Pick a diet, for example, Purina DM canned food.  The ingredient list looks like this and the percentage of products are…  Do not worry about the teeth and gums “not having some abrasion to clean off the tartar”.  Cats and dogs being fed soft meat-based diets have far fewer oral health problems than those consuming dry, grain-based diets.  Other good dry food products will demonstrate protein levels above 30 percent and fat levels above 18 percent in the Guaranteed Analysis table on the pet food label.  Usually these diets are the “Growth” or “Puppy” or “Kitten” diets… and these formulations can and should be fed for life.  If you still fear the erroneous myth about “too much protein” being “bad” for dogs and cats or that protein “causes” kidney damage, you really need some facts.  There are numerous documented reports that will allay your fears and will update you on correct research.  The myth about protein causing kidney trouble was extrapolated from research done on rodents many decades ago; the myth developed a life of its own in spite of being refuted by proper research on dogs and cats.

Getting an obese cat to lose weight needs to be done gradually… no crash diets allowed!  Cats have a unique metabolic response to fasting and whenever a feline’s food intake is rapidly and Hepatic lipidosis in cats is related to sudden reductiion of caloric intakemarkedly depressed, a serious and potentially fatal disorder can occur called Hepatic Lipidosis. 

One of the reasons for the success of a high protein diet for feline weight reduction is the importance of an amino acid called Carnitine.  Carnitine is present in good quantities in muscle tissues, but found in miniscule amounts in vegetable matter.  This amino acid plays an essential role in the uptake of stored fat reserves and conversion of fat by the liver back to into glucose.   The ability to convert stored fat into glucose for energy (and for subsequent weight loss to be accomplished) requires Carnitine in the process.  Supplementing a cat’s diet with L-Carnitine in amounts approximating 250 to 500 mg per cat per day will aid in mobilizing fat into glucose and will improve the health of a cat that is in a weight loss program.

   The Plan
First, your veterinarian needs to do a thorough physical exam, blood chemistry profile including Thyroid hormone evaluation, and record an accurate weight for the cat.  Then you should gradually… over a period of three to four weeks… add greater and greater proportions of the suggested feline weight-loss diet.  Mix the new diet with the old, slowly decreasing the percentage of the old diet and increasing the percentage of the new one.  Pay close attention to how much the cat is eating every day.  When the cat acclimates to the improved, high protein diet (fed in small amounts frequently during the day), reweigh the cat at four-week intervals.  If there is no weight loss at all, or even some weight gain, the amount of food you are allowing is simply too much.  You may be thinking in human-sized portions, not feline.  Remember the mouse.  One mouse would make a good meal for an average sized cat.  Every three to four weeks reweigh your cat on the same scale each time so that accurate weight measurements are done.  A fifteen-pound cat should not lose more than half a pound in four weeks.  (Remember the Hepatic Lipidosis problem!) 

Always be observant and report to your veterinarian any time a cat stops eating We humans have control over what and how much our pets eat.for two or more days.  (That’s one of the subtle problems with the “free choice” method of feeding.  We often do not notice that the cat’s food dish is still full until the cat is well in to a fasting mode.  When cats are sick the first clinical sign is often a loss of appetite; so a non-interactive, free choice feeding protocol provides less information to us than an interactive portion controlled feeding method.)  Any cat that hasn’t eaten in three days is in trouble!  Seven days of fasting actually impacts the cat’s immune system.

Once you have established a feeding plan that induces gradual weight loss over a period of months the cat will reach a point where weight maintenance occurs.  At this optimal weight the cat should not “look fat” nor “look skinny”.  You’d be surprised how much more active and alert the cat will be at an optimum weight.  You have successfully avoided the probability of Diabetes, arthritis and Hepatic Lipidosis.    Your cat will probably live a few extra years and have a much better quality of life… and that will make you happy, too!

To get a cat to lose weight, do the following after consulting with your veterinarian:

  1.)   Have a thorough physical exam, lab tests, and accurate weight recorded.  Be sure to rule out hypothyroidism or other metabolic disorders.

   2.)   Feed less food than you have been

   3.)   Feed foods high in protein and fat and low in carbohydrate

         4.)   Feed small portions at intervals rather than continuous free access/ free choice

  5.)   Increase the cat’s activity/exercise by enriching the cat’s  environment

          6.)   Reweigh the cat at three to four week intervals to assess your weight loss diet’s progress
      7.)   Record the total daily amount fed and if weight gain or no weight loss is noted
         8.)   Once the cat is at an idea weight, adjust the total amount fed so that the cat’s body weight remains stable.

Veterinary nutritionists suggest that we expose very young cats to a variety Kittens need high quality protein based nutrition.of food types and textures.  Cats are staunch creatures of habit and if a kitten is raised on a dry foo kibble diet only, the odds are high that it will reject any non-kibble diet later in life.  (It might not even know what to do with a captured mouse!)  Food preference can be set on canned food, too.  As kittens are developing, be sure to provide a wide variety of food types, textures, and tastes so that later in life, if weight loss diets are required, you will be able to select a type and texture that will be in the cat’s best interest.

Tell your friends about this site!

This site including all images are copyright of T J Dunn, DVM.
You may copy only the text of questions and answers for your own non-commercial use. 
Images can be requested or purchased through

View all topics