At its most basic level, achieving weight loss is as simple as decreasing the amount of calories an individual takes in and increasing the number of calories an individual burns. This holds true for dogs as well as for people, but anyone who has put their pet on a diet (or been on one themselves) can tell you that losing weight in the real world isn’t quite as simple.
A study that was presented at the 2011 American Academy of Veterinary Nutrition Clinical Nutrition & Research Symposium points to the importance of picking out the right food for dogs that need to lose a significant amount of weight. The researchers evaluated two therapeutic weight loss diets and three over the counter foods that ranged in caloric density from 218 to 492 kilocalories per cup. They determined what the nutrient intake of a dog would be if it was fed 40%, 60%, 80%, and 100% of its resting energy requirement for its current weight and compared what they found to the National Research Council’s recommended nutrient allowances. Their results showed that all of the foods were nutritionally deficient when fed at 60% or less of a dog’s resting energy requirement.
This has important implications for owners. If your dog needs to lose a lot of weight, your best option is to switch to a prescription diet that is specifically designed to help overweight or obese pets. These foods are very calorie restricted but still contain appropriate levels of protein, vitamins, minerals, and other nutrients needed to maintain good health when fed according to the label recommendations. Trying to achieve the same rate of weight loss with an over the counter food that is more calorie-dense would require a greater reduction in the amount of food that a dog eats, putting him at a higher risk for nutritional deficiencies.
Using an over the counter "diet" food can be appropriate when a dog only needs to lose a small amount of weight, but owners must compare the labels of their dog’s old and potentially new foods; the use of words like "diet" and "reduced calorie" are not well regulated. Therefore, you could easily end up switching to a food that is essentially the same or even more calorie dense than the one that you are currently feeding. Compare the calorie (kcal) counts that should be displayed on the label. Make sure they are being measured in the same way and that the total amount you will be offering throughout the day provides fewer calories than what you currently feed your dog.
Whichever type of food you choose, if you find that you have to feed significantly less than the recommended amount for your dog to lose weight, talk to your veterinarian about whether or not this continues to be your best option. Switching to a different weight loss formula could result in a quicker and healthier return to an optimal weight.
Dr. Jennifer Coates