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Weight-Loss Diets Variability

Variability of Weight-Loss Diets Confuses Owners

An evaluation of calorie density and feeding directions for commercially available pet weight-control diets reveals wide variations that may confuse owners of obese cats and dogs, according to a study by the Cummings School of Veterinary Medicine at Tufts University. The study appeared in the January issue of the Journal of the American Veterinary Medical Association.

Lisa Freeman, DVM, Ph.D., Dipl. ACVN, conducted the study with Deborah Linder, DVM. They studied 44 canine and 49 feline diets. Among the findings: Dry dog foods range in calorie density from 217 to 440 kilocalories per cup (kcal/cup). This means that if you feed the same amount of two different brands of “light” dog food, one could have twice as many calories per cup as another! The recommended daily food amount also varied, from 0.73 to 1.47 times the dog’s resting energy requirement. This means that if you fed the amount listed on the food bag you may be providing as little as 73% of the amount of calories a dog should need in a day, or as much as 47% more than the dog
needs. The diets also varied in price—from 4 cents to more than $1/10 a kilocalorie.

Dr. Freeman said owners buying pet weight-loss diets are faced with a confusing variation in calorie density, recommended intake and cost range for low-calorie foods. In addition, manufacturers vary in how they determine feeding directions for normal-weight pets. “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 Freeman, a veterinary nutrition professor. “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 caloric content. Foods so designated must adhere to a maximum kilocalorie-per-kilogram restriction. Freeman said more than half of the foods evaluated exceeded the maximum. (Foods without these designations are not required to provide the caloric content on the label.) In other words, half the pet foods labeled as lower calorie weren’t. (If the diets weren’t formulated or labeled properly in this instance, what else isn’t being done properly with these diets?)

Pet obesity is linked to pancreatitis, osteoarthritis, dermatologic disease and diabetes and may contribute to a shorter life, according to earlier studies. Because what you feed your pet is so important and obesity is such a serious problem for a pet’s health, we don’t recommend over-the-counter pet foods for obesity management. Prescription weight loss diets are formulated to a much higher standard and have been proven to be safe and effective, just as prescription medications are. We can rely on them to do exactly what they are supposed to do and the label and feeding amounts should be much more in line with reality. (The amount of food your pet needs depends on his or her activity
and metabolism, so we’ll help you to determine the best amount to feed per day.)

From an article in Veterinary Practice News, March 2010