WHAT THEY DID
Ten young and healthy intact male cats were included in the water content study, and an additional six cats underwent palatability testing.
The cats were divided into two groups—one was fed a wet diet (a commercially available canned food), while the other was fed a dry diet (made by freeze-drying the wet version) for a three-week period.
The six research cats that underwent palatability testing were offered two diets simultaneously, and their consumption and preferences were recorded. These tests were repeated multiple times, comparing various wet diets, freeze-dried diets, and the control dry diet.
WHAT THEY FOUND
For the water consumption aspect of the study, consumption of the wet diet was associated with a decrease in body weight. The reduction was small but significant, especially considering that there was no difference in body weight when the cats were fed either the freeze-dried or control diet after the two month pre-study period or at the completion of the washout period. Body composition, on the other hand, remained constant during the various trials.
In terms of palatability, the six cats greatly preferred the wet diets to either the control or freeze-dried diets, which appeared comparable.
These findings suggest that body weight can be reduced in cats by feeding wet diets, producing a voluntary reduction in energy intake. These diets have been shown in this and other studies to be highly palatable, and there is no risk of decreased nutritional content or digestibility, which can occur by bulking up diets with fiber.
The diets compared in this study had identical nutritional compositions, so study results may not translate directly to other dry and canned cat foods. Yet the results are promising, and continued research involving a broader representation of the cat population at risk of becoming obese or cats that are already obese is suggested.
Wei A, Fascetti AJ, Villaverde C, et al. Effect of water content in a canned food on voluntary food intake and body weight in cats. Am J Vet Res 2011;72(7):918-923.