Rivers Goes to Fat Camp: Episode 2, Counting Calories

The guardian of a chubby cat needs to know how much to feed on a daily basis to lead Chunky Monkey carefully down to his ideal weight. Is it reasonable to feed the amount recommended on Chunky's favorite cat food? Is it best to feed the amount a veterinarian would recommend for a cat of Chunky's ideal weight? Does it make most sense to feed more--or less--than the amount a thin cat would eat, in the interest of helping Chunky lose weight steadily but safely?

Opinions vary widely on the topic of how many calories the average cat needs to maintain a specific body weight. Even accounting for differences in age and activity level among cats, it is easy to find authors who cite a range of 15-25 calories per pound per day and others who cite a range of 20-30 calories per pound per day. The only statement on which almost everyone agrees is that, unlike manufacturers of foods meant for human consumption, pet-food manufacturers tend to label products with a serving size somewhat larger than is conducive to a svelte figure.

For example:

• The feeding guidelines for one premium kibble state that the daily serving size for an adult cat weighing 10 pounds should be ½ cup. The food in question is almost exactly 600 calories per cup. Thus the guideline is equivalent to 30 calories per pound, which is high on any scale I’ve seen mentioned anywhere, except…
• The feeding guidelines for one premium wet food state that one should feed one can for every 6-8 pounds of body weight. This loose recommendation might lead a consumer to feed a 12-pound cat two cans, for a total caloric intake exceeding 500 calories per day, more than 40 calories per pound!

 The guideline I chose to follow for Rivers’ weight loss project appears on the website of the Cornell University College of Veterinary Medicine (at http://www.vet.cornell.edu/fhc/askDr/fatcat.htm). That guideline reads as follows:

“Daily calories needed to maintain ideal weight have been calculated in a few different ways. An equation commonly used is: 30 times body weight in kilograms, plus 70.”

30 times body weight in kilograms corresponds to a little more than 13.5 times body weight in pounds. Rivers’ ideal weight is estimated at 13 pounds or less, so the number of calories needed for him to maintain that weight (should he ever reach it) comes to:

(13.5 x 13) + 70 = 175.5 + 70 = 245.5 calories

But how many calories should he consume now in order to reach that weight? Like most cat enthusiasts, I have read about the risk of hepatic lipidosis, a life-threatening complication of anorexia or precipitous weight loss in an obese cat. Here is what the Cornell article recommends as a weight-reduction plan:

“…a cat will lose weight slowly, steadily and safely if given about 70 percent of the calories needed to maintain ideal weight.”

70 percent of 245.5 calories is…only about 172 calories!

Looking at the calorie counts of Rivers’ familiar grain-free foods, I realized I could not bring myself to reduce his consumption so drastically, so I decided to see whether he would lose any weight at all if I simply fed him the amount required for maintenance of his ideal weight. For a month I fed him the following quantities daily:

•  ¼ cup of kibble, for about 150 calories (yes, it’s the fattening kibble)
• ¼ cup canned food, for about 50 calories
• 1 ounce of raw food, for about 50 calories

Yes, those quantities come to a little more than 245.5 calories, but given that he started the month at 14 pounds 14 ounces, I guessed he would lose some weight.

And indeed he did! At the end of one month, he was down to 14 pounds 9 ounces, for a weight loss of 5 ounces. Any amount up to 8 ounces would have been safe.

Next episode: No more equations, I promise!