Feeding Kitten Food to an Adult Cat

Updated: Sunday, June 02, 2019 02:24 PM

Published: Sunday, November 14, 2010 03:17 PM

Written by Elisa Katz, DVM

My two-year-old ragdoll recently started to lose weight. The vet did tests and everything came back okay, so they told me to feed her kitten food. She prefers wet food but occasionally eats dry food. I've been told it's not safe to feed an adult cat kitten food, but she seems to be doing ok on this. I would appreciate some advice.

While kitten food tends to be higher in calories, protein and fat, there is no actual danger in feeding this food to adult cats. In fact, during pregnancy and nursing, it is advised to feed the higher calorie, higher fat food to expectant and nursing mothers. The only potential danger would be obesity from over-consumption of calories and fat.

Most adult, spayed indoor cats require approximately 50 to 70 calories per kilogram of body weight per day, with the range mostly dependent upon activity level.¹ It is possible that your cat may require more calories due to a larger body type, higher activity level or if she has not been spayed.

For example, if your cat weighs 10 pounds as an ideal weight, her metabolic requirement would be between 225 and 315 calories per day:

• 10 lbs ÷ 2.2 = 4.5,
• 4.5 x 50 = 225 calories or
• 4.5 x 70 = 315 calories.

If, however, the ideal weight for your cat is really 11 pounds even though she is currently 10 pounds, her requirements would be between 250 to 350 calories a day. You will need to ask what your veterinarian believes is an ideal weight for your cat. Then make sure that you feed at least that number of calories per day. You may want to choose a food with a higher calorie content if your cat is not a big eater in order to get the appropriate number of calories into your kitty every day.

It is also possible that your cat is not consuming enough protein. Adult cats require two to three times more protein in their diet than adults of omnivorous species.² Cats evolved as animal eaters, obligate carnivores, and use protein as their energy source. In contrast, omnivores such as humans use carbohydrates, fat and protein. Cat foods can vary in protein content from 30% up to 50% on a dry matter basis. Try to find a food that is toward the higher level of protein to ensure your cat consumes adequate levels of this vital nutrient. For these reasons, I recommend sticking to canned food, as it is higher in protein and has less carbohydrate. Cats cannot properly process and use carbohydrates such as grains.³

Foods can vary a lot from one brand to another as far as calorie, protein and fat content. It is best to read labels and request information on these three parameters from the manufacturer. Most pet food companies will have contact information or nutritional information on their websites to provide this information. Be sure that you have this information on a dry matter basis so that you can equally compare foods with varying moisture content.

If you need to calculate DMB for yourself, here is an example:

• Assume the guaranteed analysis for a particular food lists protein at 10%, fat at 5% and a moisture content of 78%,
• Subtract the moisture percentage from 100 to get 22% dry matter or .22,
• Divide 10 by .22 and round to 45.

In this example, on a dry matter basis the food is 45% protein and 23% fat. Do this for other foods with varying moisture contents so that you can easily compare.

You may want to consider placing your ragdoll on a raw or partially raw cat food diet. This type of diet would be closer to what your cat would eat naturally, as well as delivering adequate amounts of protein, fat and calories when fed properly. Commercially prepared raw cat food is typically 40 to 60% protein and 20 to 30% fat DMB.⁴ For comparison, a wild mouse is about 59% protein and 20% fat DMB.⁵ There are many commercial brands of raw food for cats, or you can try your hand at homemade cat food.

If your cat does not gain weight after a few months of consuming adequate amounts of calories and protein, you may want to consult your vet about pursuing further diagnostic tests to rule out diseases such as inflammatory bowel disease – a syndrome that can often be successfully treated by a change in diet to promote better cat nutrition and health.

Note: Feline Nutrition provides feline health and nutrition information as a public service. Diagnosis and treatment of specific conditions should always be in consultation with your own veterinarian. Feline Nutrition disclaims all warranties and liability related to the veterinary advice and information provided on this site.

Dr. Elisa Katz, DVM, is a graduate of Ohio State University and is the owner of Natural Pet Animal Hospital in Bourbonnais, Illinois. She practices holistic and integrative medicine focusing on proper diet and nutrition. Dr. Katz shares her home with four kitties and one dog.

1. Claudia A. Kirk, Jacques Debraekeleer and P. Jane Armstrong, "Normal Cats," Small Animal Clinical Nutrition,4th ed. Walsworth Publishing Company, 2000, 307-309.

2. Kirk and others, 299.

3. Debra L. Zoran, DVM, PhD, DACVIM, "The Carnivore Connection to Nutrition in Cats," Journal of the American Veterinary Medical Association 221, no. 11, December 1, 2002.

4. Some examples: Fegnion Raw Chicken Cat Food 60% protein, 25% fat DMB; Nature's Variety Rabbit Formula 40.6% protein, 25% fat DMB.

5. Ellen S. Dierenfeld, PhD, Heather L. Alcorn, BS and Krista L. Jacobsen, MS, "Nutrient Composition of Whole Vertebrate Prey (Excluding Fish) Fed in Zoos," U.S. Department of Agriculture, May 2002.