St. Louis-Results from a Nestlé Purina study confirm the link between body fat and certain health conditions in dogs.
The article, recently published in the Journal of Nutrition, also established a link between the length of time dogs were
overweight, their longevity, and how early in life certain health conditions became clinically evident. The findings are additional
results from the landmark Purina Life Span Study, the first completed lifelong canine diet restriction study.
Researchers discovered that excess body fat reduces insulin sensitivity, which inhibits the ability of cells to absorb glucose
quickly and efficiently. Glucose and insulin left in the bloodstream can hinder the ability of organs, tissues and body systems
to function properly, which can result in the development of some chronic health conditions.
"The significance of the latest published information is what we've learned about the lifetime effects of impaired glucose
metabolism and insulin sensitivity," says Brian T. Larson, Ph.D., Nestlé Purina nutrition research scientist and lead author
of the article Improved Glucose Tolerance with Lifetime Diet Restriction Favorably Affects Disease and Survival in Dogs.
"Over time, the pathogenic effects of excess glucose and insulin in the bloodstream can alter glucose metabolism and cause
cellular damage and metabolic changes.
"In overweight human beings," Larson explains, "we see a similar chain of events unfold. The result is that individuals with
excess body fat and insulin resistance are more likely to develop Type II (adult-onset) diabetes. Dogs do not develop diabetes
to the same degree as people; instead, they can develop other health conditions, including osteoarthritis (OA) and a number
of metabolic conditions that can affect the function of various internal organs."
In the Life Span Study, control-fed dogs not only had a greater propensity to require treatment for chronic health conditions
such as OA, but also needed that treatment earlier than their lean-fed littermates.
Further analysis indicated that the impact of compromised glucose tolerance and insulin sensitivity on health occurred when
the dogs were moderately overweight, not grossly obese.
The study showed that on average, insulin resistance began to appear in dogs that scored a 6 - 6.5 (overweight) on the 9-point
Nestlé Purina Body Condition System (BCS), with 4.5 being ideal body condition and 8 to 9 being obese.
Larson stressed the significance of the long-term state of insulin resistance that occurs in dogs that are overweight throughout
"The longer dogs are overweight, the more physiological damage they can suffer."
According to Larson's co-author, Dennis Lawler, DVM, one of the principal investigators in the Purina Life Span Study, the
clinical implications of this new information should be of interest to both veterinary professionals and dog owners.
Lawler emphasized the information about the correlation between body fat mass and insulin sensitivity (in the Life Span Study,
lean-fed dogs were 58 percent more insulin-sensitive than controls) can be applied to the way veterinary medicine is practiced
"Any veterinarian who has advised a client to implement a weight-loss program for a patient knows how frustrating it can be.
Many owners simply don't understand that having a 'pleasingly plump' puppy is not necessarily a good thing for his overall
health-nor do they realize that the longer the dog is overweight, the harder it will be to restore normal glucose metabolism."
"Our hope at Nestlé Purina is that this new information will compel more veterinarians-and owners-to take action in helping
keep dogs from becoming overweight or implementing a weight management program to restore animals to healthy, normal body
condition," Lawler concluded.