Every dog is different, and depending on things like their breed, size, age, and health, their particular dietary requirements may also be different, including what you should feed them, and how much.
But what about how often? A new study that assessed over 10,000 dogs offers some startling insights into the apparent links between feeding frequency and canine health – and the key takeaway is definitely food for thought.
According to the research, adult dogs that are fed only once per day tend to score significantly better across several indicators of health, compared with dogs that are fed more often.
"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," the research team, led by first author and canine health researcher Emily Bray from the University of Arizona, explains in the new paper.
The results are gleaned from data collected by a broad, ongoing canine health study called the Dog Aging Project.
While you shouldn't rush out and change your feeding routine just yet, the findings suggest that the kinds of benefits seemingly delivered by time-restricted eating – mostly seen in laboratory experiments involving rodents to date – might also extend to companion dogs.
Not that the results aren't something of a surprise – even for the scientists doing the research.
"We weren't confident at all that we would see any differences in dogs' health or cognition based on feeding frequency," explained senior author and biostatistician Kathleen Kerr from the University of Washington, back when the preliminary results were announced in December.
"I think we would have been excited to see an association between feeding frequency and health in just one domain. I was surprised to see associations in so many domains."
While a feeding frequency of one meal per day was linked with better outcomes for dogs in some areas, in other domains it wasn't so clear. Measurements for disease risk in terms of cardiac, skin, and neurological health, as well as cancer incidence, didn't show statistically significant effects.
Beyond that, the researchers acknowledge a number of limitations to bear in mind with their study. All the feeding data was self-reported by dog owners – meaning it's subject to errors in their recollection and interpretation – and the study wasn't able to tease apart the possible influence of caloric restriction (which wasn't measured in the study) from feeding frequency.
Nonetheless, despite the limitations, the team says this is the largest study to date of feeding frequency conducted in companion dogs, and there's clearly something going on here to suggest that feeding your dog only once per day is linked with certain benefits to their health.
As for what that is, exactly, it remains unknown, and the researchers emphasize that the results only show an association, and do not demonstrate causality – meaning we can't conclude that lower frequency of feeding actually causes better health in dogs.
For example, there could be lots of reasons why dogs with worse health might be fed more frequently than healthy dogs (being fed extra meals to take medication, for example), as Bray points out.
Until much more is known about the underlying mechanisms for this apparent phenomenon – and subsequent research can somehow explain the results further – nobody should change how often they feed their dog based on this one study, the researchers say.
"However, if supported by future studies, it may be prudent to revisit the currently predominant recommendation that adult dogs be fed twice daily," the team concludes.
"The rationale for twice-daily feeding in dogs is obscure… and our study suggests that more frequent feeding may, in fact, be suboptimal for several age-related health outcomes."
The findings are reported in GeroScience.