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Written by leading veterinarians to provide you with the information you need to care for your pets.

Your cat's nutrition is important for a healthy & happy life. petMD experts help you to know what to feed your cat, how much food to feed, and the differences in cat foods, so your cat gets optimum nutrition.
Nutrition Nuggets is the newest offshoot of petMD's Cat Nutrition Center. Each week Dr. Coates will use her expertise and wisdom to blog about the intricacies of cat nutrition.

How Caloric Needs Change with Time

February 15, 2013 / (2) comments

Over the last couple of years, I’ve been afflicted with something that most people who reach a "certain" age have experienced — a declining metabolic rate. It used to be that I could pretty much eat whatever I wanted. As long as I remained reasonably active my weight remained stable. Not so any more. I have to pay much closer attention to how many calories I’m taking in over the course of the day. Otherwise, the jeans start to get a little too tight. Sigh.

Research has shown that maintenance energy requirements (MER) decrease with age in people and in dogs. Cats, on the other hand, are a little different (aren’t they always?). Their maintenance energy requirements tend to decrease, just like ours, until they are around 11 or 12 years old, at which point they actually begin to increase again.

Oh, if this were only the case for people. Eleven in cat years corresponds to approximately 60 in people years. For most folks, a higher MER would be a most welcome 60th birthday present!

The reason behind the increased energy needs of older cats appears to be associated with a decrease in their ability to digest fat and sometimes protein. So, if your feline senior citizen is having trouble maintaining her weight on her current diet, consider switching to a food with a higher caloric density that is made from good quality, highly digestible fat and protein sources.

The caloric needs of cats change drastically throughout their lives. A kitten needs a lot of energy to power growth, development, and play. That’s why kitten food has such a high caloric density in comparison to foods designed for adults. Once growth has stopped, a cat’s energy needs decline dramatically. When a cat reaches middle age (6 to 12 years of age or so), her caloric needs decrease even more as her lean body mass declines, but eventually she starts to need more calories as her ability to digest fat, and possibly protein, declines.

Spaying and neutering have a big effect, too. Several studies have looked at this, and typically cats should receive around 25 percent fewer calories after being spayed/neutered than they took in before the surgery.

wners need to be aware that cats at different stages of life have dramatically different nutritional needs and feed them appropriately. Weighing cats at home on a monthly basis is an easy way to note small changes in body weight while they are still (relatively) simple to address.

  1. Step on the bathroom scale with your cat in your arms
  2. Put the cat down, and weigh yourself
  3. Subtract your weight from the total and you have your cat’s weight
  4. Keep a running record in a journal, spreadsheet, or chart

What look like small changes in body weight are actually very significant. To put it in human terms. A 10 pound cat that gains 1 pound is equivalent to a 150 pound person gaining 15 pounds. Or, when a cat that is normally 8 pounds weighs in at 7 pounds, she has just lost 12.5 percent of her body weight, which correlates to almost 19 pounds for our 150 pound person. That’s a change worth addressing, don’t you think?

Dr. Jennifer Coates

Image: Blake Facey / via Flickr

Comments  2

Leave Comment
  • Weight in Cats
    02/15/2013 10:11pm

    I've always tried to be aware of subtle weight loss with my cats. As they get older, there is always the fear of kidney disease, hyperthyroidism or diabetes.

    In my opinion, any weight change should be addressed with the doctor.

  • Elderly cat
    02/16/2013 02:42pm

    My oldest cat is 25 years old. He has lost a lot of weight, and I try to get him to eat, but he has little appetite. About 5 years ago the vet said he had signs of kidney failure, but Sylvester keeps right on going. As long as he isn't showing any signs of suffering, I let him judge how much he wants to eat. The vet told me "you must be doing something right." If he gets to the point where he is suffering, I will have him put to sleep. But for now, I just love and enjoy him.




Photo of Jennifer

... graduated with honors from the Virginia-Maryland Regional College of Veterinary Medicine in 1999. In the years since, she has practiced veterinary medicine in Virginia, Wyoming, and Colorado. She is the author of several books about veterinary medicine and animal care, including the Dictionary of Veterinary Terms, Vet-Speak Deciphered for the Non-Veterinarian .

Jennifer also writes short stories that focus on the strength and importance of the human-animal bond and freelance articles relating to a variety of animal care and veterinary topics. Dr. Coates lives in Fort Collins, Colorado with her husband, daughter, and pets.