Canine metabolism responds better to fat than carbs, research suggests

A high-carbohydrate kibble diet and a low-carb raw meat diet have markedly different effects on dogs’ energy metabolism, according to a new study by the DogRisk research group at the University of Helsinki published in The veterinary magazine.

In the study, 46 Staffordshire Bull Terriers were fed either kibble or raw food for an average of 4.5 months. The kibble diet was high in carbohydrates with no fiber, while the raw diet was high in fat and had no carbohydrates without fiber. The researchers measured several biomarkers before and after the trial, including blood sugar, insulin, cholesterol, triglycerides, ketone bodies and body weight.

The main important findings of the study are:

• Dogs on the kibble diet showed long-term increases in blood sugar, blood lipids and body weight.
• Dogs fed raw food showed decreased levels of blood sugar, blood lipids and glucagon.
• Both groups had increased ketone bodies, but levels were significantly higher in the raw food group, indicating a greater reliance on fat for energy.
• The raw food group also showed a decrease in the triglyceride-glucose index, a marker of insulin resistance previously used only in human studies.

“Interestingly, the kibble diet was associated with changes often linked to unfavorable metabolic health, while the raw food diet promoted metabolic responses generally considered favorable,” said Dr. Sarah Holm, DVM and Ph.D., lead researcher of the study from the DogRisk research group at the Faculty of Veterinary Medicine at the University of Helsinki. “More research is needed to understand the long-term health implications of these two dietary strategies.”

Dr. Anna Hielm-Björkman, DVM and professor, who leads the DogRisk group, added: “This is an excellent example of One Health research. Our results mirror similar, and sometimes controversial, human studies suggesting that high-fat diets actually lower cholesterol and triglycerides, while high-carbohydrate diets increase blood lipids and blood sugar levels over the long term, a known precursor to type 2 diabetes in humans.

The study highlights the potential of using dogs as models for research into human metabolism and opens the door to further research into how diet affects species health.