You would think the answer to such a question would be easy. For years, Weight Watchers has been telling people how much to eat. But the answer for overweight dogs is not nearly as simple. All of the methods used to determine how much food should be fed to a dieting dog have drawbacks. I hope this post helps you understand why finding the "ideal number of calories" for a dog diet is so difficult.
Breed Ideal Weight
For years, breed ideal weight has been the benchmark for establishing requirements for the dieting dog. The information is readily available and easy to use. Once the ideal weight is determined for a specific dog, the dog is then fed 70-90 percent of the recommended amount of food to reach that weight.
As we have discussed previously, weight variations are quite wide for some breeds and particularly wide between males and females in large breeds. Ideal weights for dissimilar body type breeds (labradoodles and puggles, for example) can also be quite variable. Ideal weight can range from 2-5 pounds in small dogs and up to 20 pounds in larger breeds. Because every pound requires 53 additional calories, assigning a dog the "wrong" ideal weight could mean overfeeding from 100 to 1000 calories! This could result in little weight loss and perhaps even weight gain.
On the other hand, feeding a grossly obese small dog 70 percent of the required amount of food for its ideal weight could mean feeding only 1/3 to 1/4 of its present diet. As a dieter myself, I can say that would be downright cruel.
Calculations Using Present Weight
Some experts recommend feeding the amount of food necessary to maintain the resting metabolic rate of a dog’s existing weight. Others suggest feeding 60 percent of the total daily energy requirement for present weight. And still others suggest restricting calories based on a calculated 1-2 percent body weight loss per week.
Although these three approaches seem quite different, the calculations all result in about the same amount of calorie restriction. All of these methods are generally successful for most dogs. Often these methods require staging, meaning that recalculations are necessary when weight loss decreases or long weight plateaus occur. This most often is necessary in severely obese pets. The third method relies on the commonly held belief that every restriction or exertion of 3,500 calories results in the loss of 1 pound of fat. This may not be the case.
Research released last year in a leading medical journal suggests that the loss of 1 pound of fat may require over 10,000 calories due to the metabolic adaptations the body makes during dieting. It went on to say that only half of the weight is lost in the first year with the other half lost over the next two years. These findings certainly give support to the notion of long term lifestyle change instead of short term dieting. The relevance of this research to dogs has not yet been determined, but it certainly might help explain why dieting is so difficult, even for dogs.
The Bottom Line
There is no magic number of calories to feed the overweight dog. There is only a starting point that may require many adjustments. This is why it is so important to partner with your veterinarian in a closely supervised weight loss and weight management program. Your veterinarian can identify that starting point and monitor progress. I weigh my overweight patients every two weeks until I am satisfied that they are losing predictably. Then I weigh them monthly until we reach our target body condition score (BCS Chart). When they achieve a "3" in the 5-point system they are at their unique ideal weight. That is the weight we use for all future feeding recommendations. Ask your vet about your dog’s specific starting point.
Next time we will discuss feeding the overweight cat.
Dr. Ken Tudor