An analysis of a survey of more than 24,000 pet canines found that dogs that were fed only once a day were significantly less likely to be diagnosed with age-related diseases than dogs that had more meals. For now, veterinarians say dog owners should not change their pets' current feeding regimes until further research establishes a causal link.
You may have heard about intermittent fasting, eating only during a specific time. While most diets focus on what you eat, such as consuming fewer carbs or fats, intermittent fasting is all about when you eat -- the calories and nutrients themselves matter too, but they're secondary in this instance.
And unlike most fad diets, science actually supports a range of health benefits that have been associated with fasting. A 2021 study published in the journal Nature Aging analyzed the effects of different fasting methods on longevity in organisms ranging from yeast to humans. The researchers found that the alternation of fasting and refeeding periods reduces risk factors for aging, diabetes, autoimmunity, cardiovascular disease, neurodegeneration, and cancer, linking these effects to major nutrient-sensing signaling pathways.
The metabolic and cellular responses triggered by fasting may explain the most recent findings by researchers from the University of Washington, who concluded that dogs that ate just once a day were advancing in age more healthily than dogs fed twice or more per day. Dogs evolved from wolves, predators that would often go for days without eating until they found their next prey, so it would make sense that time-restricted feeding may be beneficial for them.
The study involved thousands of dogs as part of the Dog Aging Project, an ambitious initiative that aims to follow thousands of dogs for ten years in order to identify the biological and environmental factors that maximize healthy longevity.
"Controlling for sex, age, breed, and other potential confounders, we found that dogs fed once daily rather than more frequently had lower mean scores on a cognitive dysfunction scale, and lower odds of having gastrointestinal, dental, orthopedic, kidney/urinary, and liver/pancreas disorders. Therefore, our findings suggest that once-a-day feeding in dogs is associated with improved health across multiple body systems," the researchers wrote in their study that appeared in the pre-print journal bioRxiv.
Although the new study on dog feeding patterns provides compelling evidence that fasting may protect pets from age-related conditions, the findings are purely correlative at this point. The survey data did not include information about what exactly each dog ate or the number of calories, which can be very important. For instance, dogs who are fed multiple times a day may tend to overeat, which could lead to obesity, an important risk factor in a range of diseases.
Ideally, the researchers would like to perform a randomized trial in which they can monitor canine diets over a long period of time and measure the effects on their health in a controlled setting.
In the meantime, pet owners are advised to not alter their dogs' diets until further evidence surfaces. At the moment, most veterinary associations advise feeding dogs twice a day.