What dog owner wouldn't want more healthy years with his pet? A study from Nestlé© Purina PetCare shows pet owners may have the power of longevity in their own hands.

In the first-ever lifelong canine diet restriction study, Purina researchers have proven that a dog's median life span can be extended by 15 percent - nearly two years for the Labrador Retrievers in this study - by feeding to ideal body condition through diet restriction, according to findings published in the edition of the Journal of the American Veterinary Medical Association.

The 14-year Purina "Life Span" study found that dogs that consumed 25 percent fewer calories than their littermates during their lifetimes maintained a lean or ideal body condition, resulting in a longer life. According to experts, the study provides the most significant data to date on the effects of diet restriction as the ...

• First diet restriction study completed for the entire life span of a larger mammal
• First completed study to document that diet restriction increases survival time in mammals larger than rodents
• First study to achieve these health benefits for dogs with moderate reduction of food intake (25 percent versus the 30 percent to 50 percent typically used in rodent studies)

"We all know that obesity, whether in humans or canines, is generally bad for health" says Dennis Lawler, DVM, Purina scientist and a lead study investigator. "What's exciting about this study is that, for the first time in a larger mammal, we have shown scientifically that by simply feeding to maintain ideal body condition throughout a dog's life, we can increase length of life while delaying the visible signs of aging. That's powerful stuff."

Study Design ... A Lifetime of Information
When the study began, 48 eight-week-old Labrador Retriever dogs from seven litters were paired within their litters according to gender and body weight and randomly assigned to either a control or restricted-fed group. The control group was allowed to eat an unlimited, or free choice, amount of food during 15-minute daily feedings. Dogs in the restricted, or "lean-fed" group were fed 75 percent of the amount eaten by their paired littermates.

All dogs were fed the same 100 percent nutritionally complete and balanced diets (puppy, then adult) for the entire period of the study, from eight weeks of age until death – only the quantity was different.

Dogs were weighed weekly as puppies, periodically as adolescents and then weekly as adults. Beginning at six years of age, they were evaluated annually for ideal body condition using the Purina Body Condition System™, a scientifically validated standard used by veterinarians to evaluate body physique in pets to assess weight and health.

Lean or ideal body condition refers to the evaluation of body physique in pets as an indicator of their overall health and well-being, generally falling into three categories: underfed, ideal and overfed. Be sure to read more about Ideal Body Condition and the Purina Body Condition System.

• Underfed: Ribs are highly visible.
• Ideal Body Condition: Can feel and see outline of ribs. Dog has a waist when viewed from above. Belly is tucked up when viewed from the side.
• Overfed: Dog has no waist when viewed from above. Belly is rounded when viewed from the side.

Other health indicators, including body fat mass, lean body mass, bone mass and glucose, glucose and insulin use, and cholesterol and triglyceride levels were measured annually to assess condition and health.

Study Results ... Living Longer
Study findings revealed that the median life span of the lean-fed dogs was extended by 15 percent or nearly two years. Median life span (the age at which 50 percent of dogs in the group died) was 11.2 years for the control group versus 13 years for the lean-fed dogs.

By age 10, only three lean-fed dogs had died, compared to seven control group dogs. At the end of the twelfth year, 11 lean-fed dogs were alive with only one control dog surviving. Twenty-five percent of the lean-fed group survived to 13.5 years, while none of the control group dogs lived to 13.5 years.

The study showed that the lean-fed dogs maintained a significantly leaner body condition from 6 to 12 years of age than the control group dogs, with mean body condition scores between 4 - 5 (ideal) and 6 - 7 (overfed), respectively. On average, the lean-fed group weighed less, had lower body fat, and after a certain age, experienced a two-year delay in the loss of lean body mass as they aged, compared to the control group dogs.

In addition, according to observations of the researchers, the control dogs exhibited more visible signs of aging, such as graying muzzles, impaired gaits and reduced activity, at an earlier age than the lean-fed dogs.

This study reveals the crucial role ideal body condition plays in health and longevity. However, obesity remains the number one nutritional problem among dogs. Studies have documented that at least 25 percent of dogs in the U.S. may be overweight.

To maximize their dogs' health, dog owners should learn how to recognize the signs of obesity and feed to ideal body condition.

More about body condition...