The pet obesity problem has sparked an interest in over-the-counter weight control diets by commercial dog food manufacturers. Unfortunately, their concern is more of a marketing opportunity rather than a serious attempt to solve the problem. There are three reasons that these diets may actually cause weight maintenance or even weight gain rather than weight loss.
1) Weight Control Diets Have too Many Calories
Over-the-counter weight management diets contain about 100 more calories per cup of dry food than veterinary weight control products by the same companies. These diets only offer 20-50 fewer calories per cup than regular maintenance diets. This is hardly enough calorie restriction to make a significant difference.
2) The Feeding Instructions are too Generous
The claims on the feeding instructions of over-the-counter weight management diets claim a 25% reduction in calories that promotes weight loss. The comparison is made with reference to the calorie requirements for more demanding life stages of dogs. The instructions are 25% less than the calorie needs of unneutered, active dogs. But the instructions are exactly or only slightly less than the daily caloric needs of the average neutered, inactive couch potato dog. This is the group of dogs most likely to be overweight or obese. These instructions would tend to maintain the present weight or even encourage weight gain if owners fed at the maximum level of the recommended feeding range.
3) Calorie Counts are Extremely Variable Between Brands
There is no standardization of the calorie content of over-the-counter weight control diets. A study in 2010 by researchers at the Tufts University Veterinary School discovered that the variability of calorie density varied tremendously in these diets. On average, the study found dry formulas varied as much as 200 calories per cup and wet, canned formulas varied as much as 90 calories per can.
These differences are significant, especially if dog owners switched weight management diets and failed to change meal amounts. A “dieting” dog fed dry food could actually gain 21lbs. over the course of a year!
Dr. Ken Tudor,
THE DOG DIETITIAN