How much should I feed my cat? A vet answers

A grey cat eating dry food from a saucer
(Image credit: Getty)

When I tell a client their cat is overweight, “how much should I feed my cat, anyway?” is a question they often ask. Unfortunately, while that sounds like a pretty simple question, there isn’t an easy answer. Even when feeding them the best cat food, the quantity they need to eat in order to maintain a healthy weight can vary significantly, depending on genetic factors, your cat’s physical activity level, and the calorie density of your cat’s diet. Determining how much to feed your cat each day typically requires research, combined with some trial and error. 

Obesity poses a health risk to cats

The question, 'how much should I feed my cat?' has prompted numerous investigations. In a 2017 study, the Association for Pet Obesity Prevention found that 59.5% of cats in the United States are classified as overweight or obese.This isn’t just a cosmetic issue; being overweight or obese can shorten a cat’s lifespan. Obese cats are at higher risk of a number of serious medical conditions, including diabetes, arthritis, and bladder stones. They also often struggle to groom themselves, resulting in skin and bladder infections.

While many of the health issues associated with obesity develop gradually over time, obese cats are also prone to an acute illness. Hepatic lipidosis, or fatty liver disease, is a condition that can take a cat from apparently healthy to critically ill in just a matter of days. It occurs when an obese cat goes without eating (or eats significantly less than usual) for a period of several days. The body’s fat stores are rapidly mobilized to provide energy, but all of this fat floods into the liver and interferes with normal liver function. Cats with hepatic lipidosis rapidly develop icterus or jaundice (yellow eyes and gums), vomiting, and diarrhea. If not treated quickly and aggressively, hepatic lipidosis can be fatal within a matter of days. 

Given the long-term and acute health risks associated with obesity, all cats should be maintained at a healthy body weight. If you’re worried about your cat’s weight, work with your veterinarian to develop an appropriate weight-loss plan. Don’t start your cat on a crash diet without veterinary guidance, because the last thing you want is for your efforts at a healthier lifestyle to cause hepatic lipidosis.  

Should you feed dry food or wet food? 

Well-balanced feline diets are available in both dry and wet (canned) formulations. Sometimes it’s hard to know which is a better option. 

Most veterinarians feel that cats benefit from a wet diet. These diets are often lower in carbohydrates than dry food, and cats don’t need high levels of dietary carbohydrates. Additionally, feeding the best wet cat food increases a cat’s water intake. Many cats drink limited amounts of water, and dehydration may play a role in the development of chronic kidney disease and lower urinary tract disease. (Buying a pet water fountain is another way to encourage drinking). 

While wet foods have benefits, they also have their drawbacks. Wet food is often more expensive to feed than the best dry cat foods. Additionally, wet food can spoil in your cat’s food bowl; anything that is not eaten within a couple of hours must be discarded. Feeding wet food also typically requires storing partial cans – covered – in the refrigerator. While these may all be relatively mild inconveniences, they lead some cat owners to prefer dry food over canned food. 

If you’re unsure of whether to feed your cat dry or canned food, talk to your veterinarian. They are familiar with your cat’s health history and can help you make the most appropriate decision for your cat. 

Use label recommendations as a guide for feeding

Each cat food has different feeding guidelines, because foods differ in caloric density. On the label of your can or bag of cat food, look for a chart that provides recommended daily feeding guidelines, based on body weight. Once you have determined how much your cat needs to eat each day, based on their healthy weight, divide this amount into two or three separate meals. 

When you measure your cat’s food, accuracy is important. Dry food should be measured using a measuring cup; don’t try to 'eyeball' it, because a small increase in food can translate to a large increase in calories! Wet food is often measured as whole or partial cans, which makes measurement a little more straightforward. 

Keep in mind that feeding guidelines are not an exact, one-size-fits-all recommendation. The cats involved in feeding studies may be more active than the average indoor house cat. Additionally, every cat has a slightly different metabolism. 

how much should I feed my cat

(Image credit: Getty Images)

Monitor your cat and make changes as needed

Some cats need more or less food than the label guidelines recommend. Monitor your cat’s body condition (overall appearance) to ensure that they are not becoming overweight or underweight. A cat that is at a healthy weight will have an obvious waist when viewed from the side or from above. You should also be able to easily feel your cat’s ribs, but not be able to see them. If you’re concerned that your cat is getting overweight, read our guide to healthy weight loss for cats.

Give your cat several weeks to adjust after any food change, then re-evaluate your cat’s body condition. If your cat is gaining weight, decrease their daily food intake by approximately 10%. If your cat is losing weight, increase their food quantity by 10%. Continue making these small changes every few weeks until you arrive at a food quantity that allows your cat to maintain a healthy weight. 

Weight management will keep your cat healthy

The question, 'how much should I feed my cat?' is usually asked in the context of weight management. It’s relatively uncommon for a pet cat to be underweight, but overweight cats are a common occurrence. By following label recommendations, measuring your cat’s meals, and monitoring your cat’s body condition closely, you can ensure that your cat remains at a healthy body weight, and avoids the negative impacts associated with obesity. 

If you’re keen to ensure you’re giving your kitty the best in feline nutrition, check out our vet’s top tips for feeding a cat properly. 

Catherine Barnette DVM

Dr. Barnette is a graduate of the University of Florida, where she received both her B.S. in Zoology and her Doctor of Veterinary Medicine (DVM). She has 15 years of clinical experience as a small animal veterinarian, treating dogs, cats, and occasional exotic patients. She now works as a freelance veterinary writer, creating educational content for veterinarians, veterinary team members, and dedicated pet owners. Dr. Barnette lives in southwest Florida with her husband and daughter (plus two cats, a dog, and a rescued dove!) and enjoys kayaking, biking, and hiking. Learn more about Dr. Barnette at www.linkedin.com/in/catherinebarnette.