An extensive 14-year study has just been completed, revealing that a calorie-restricted diet results in dogs living a median 1.8 years longer than the average dog.

The study was conducted by University of Pennsylvania and published in the Journal of the American Veterinary Medical Association (May 2002).

In addition, these same dogs are also slower to develop chronic diseases, such as osteoarthritis, implying that not only the quantity but the quality of life is extended.

"Dogs in the calorie-restricted group didn't require treatment for osteoarthritis until a mean age of 13.3 years, fully three years later than the dogs in the control group," says Gail K Smith, professor of orthopedic surgery at Penn. "Because osteoarthritis is painful, this deferral represents a substantial boost in quality of life."