Posted: January 28, 2010, 3 a.m. EST
A recent evaluation of calorie density and feeding directions for commercially available diets made for weight control in cats and dogs reveals wide variations, which may confuse owners of
obese pets, according to the study by the Cummings School of Veterinary Medicine at Tufts University.
According to Lisa Freeman, DVM, the study’s co-author along with 2010 Cummings School graduate Deborah Linder, DVM, pet owners buying weight-loss diets for their pets are faced with a confusing two-fold variation in calorie density, recommended intake, and wide range in the cost of low-calorie foods. In addition, variation exists among manufacturers with regard to the way by which feeding directions for normal-weight animals are determined.
The study appears this month in the Journal of the American Veterinary Medical Association. Linder and Freeman studied 44 canine and 49 feline diets.
Among the findings is that dry dog foods range in calorie density from 217 to 440 kilocalories per cup (kcal/cup) and a recommended intake that ranged from 0.73 to 1.47 times the dog’s resting energy requirement. The diets also varied in price — from 4 cents to more than $1.10 per kilocalorie.
As a result of variability among diets and recommendations for weight loss as well as the inherent differences among pets, the study states, diet programs for overweight or obese pets are a challenging endeavor for pet owners and veterinarians. The other problem detected was a wide range in feeding directions and high variability in estimates of calorie requirements for weight loss, which make weight loss unlikely with most diets.
“There is so much information — and misinformation — about pet foods, it’s understandable that people are confused about what to feed their dogs and cats,” said Dr. Freeman, professor of nutrition at Tufts University’s Cummings School of Veterinary Medicine. “To counteract these myths, people are accustomed to turning to the labels on food - but, as this study shows, packaging might not always be a reliable source of information.”
Federal guidelines require pet foods labeled “lite,” “light,” “low calorie” or “less calorie" to provide the caloric content. Foods designated as light, lite, or low-calorie must also adhere to a maximum kilocalorie per kilogram restriction.
However, Freeman said that more than half of the foods evaluated exceeded this maximum. Foods without these designations are allowed, but not required, to provide the caloric content on the label.
Another key issue the study identifies involves the high variability in feeding recommendations for weight loss based on the labels that were evaluated. For most of the diets, pets would not lose weight or would gain weight if owners followed the labels’ feeding directions and didn’t adjust according to their pet’s individual calorie requirements, according to the study.
Obesity in pets is linked to numerous diseases, including pancreatitis, osteoarthritis, dermatologic disease and diabetes — and may contribute to a shorter lifespan, according to earlier published studies.