Pet owners keeping watch on the girth of their furry friends are faced with “confusing two-fold variation in calorie density, recommended intake and cost” of low-calorie pet foods. A study by the Cummings School of Veterinary Medicine at Tufts University, which examined up to 100 commercially available calorie control diets, found that dry dog foods range in calorie density from 217 to 440 kilocalories per cup. While the recommended intake ranged from 0.73 to 1.47 times the dog’s resting energy requirement. Price variations were also stark. “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," co-author of the report Dr. Lisa Freeman, professor of nutrition at Tufts University's Cummings School of Veterinary Medicine, told Science Daily. "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."