Dogs that are fed one meal per day appear to have better cognitive function and health than those fed multiple times.

By examining data from 47,000 pet dogs, researchers have discovered a link between health and meal consumption, indicating that calorie restriction can slow or reverse aspects of aging.

Emily Bray, from the University of Arizona's Canine Cognition Center, and her team were looking to see if a diet restricted to one meal per day had any influence on canine health.

Previous research in rodents has shown intermittent fasting results in better memory and spatial learning.

"Our initial hypothesis was that going a longer time between meals would be similarly associated with preservation of cognitive function in older dogs, and we could look at this by capitalizing on the fact that some dogs are fed once per day while others are fed more frequently," she told Newsweek.

Bray and her colleagues used data from The Dog Aging Project, which aims to better understand how genes, lifestyle and environment impact canine aging. The goal is to help dogs live healthier lives for longer.

The latest research appears on the pre-print website bioRxiv. The article has not yet been peer reviewed or published in a journal, so the findings should be taken with a level of caution.

In the paper, the team looked at associations between feeding frequency, cognitive function and nine categories of health. Owners were asked to fill out a survey of their dog's cognitive health.

After controlling for age, sex and breed, the team found dogs that were only fed once per day, rather than multiple times, appeared to have lower scores of cognitive disfunction, equivalent to the difference between a 7-year-old and 11-year-old dog.

They were also less likely to have a range of health problems, including gastrointestinal, dental, bone, kidney and liver disorders.

"While the results were in the direction that we would predict based on studies in rodents, it was still surprising because this is the first study that has asked this question for thousands of dogs living in the natural environment, and we saw the effects on multiple health systems," Bray said.

dogs begging
Stock photo of dogs begging for food. Researchers have found a link between feeding dogs once per day and better cognitive function and health. Getty Images

In lab experiments on rodents, she said, intermittent fasting appears to provide benefits on a cellular level by modulating the biology of aging. The research on dogs was purely observational, so why fasting appears to provide health benefits is unknown.

"We have found strong evidence of an association between feeding frequency and health, but we have not shown that less frequent feeding causes better health outcomes," Bray said.

"There are various reasons why dogs with worse health might be fed more frequently. For example, dogs on prescription medication might need to be fed more frequently in order to get their medication in their food."

The ASPCA (American Society for the Prevention of Cruelty to Animals) recommends feeding all dogs twice per day. Owners are advised to divide the amount of food their dogs require into two. Each meal should be between eight and 12 hours apart.

The American Kennel Club also says dogs should be fed two meals per day, as does the animal hospital chain VCA.

Bray also said owners should not start feeding their dogs once per day: "This paper is not meant to be treated as veterinary advice. We think this study is an intriguing first step to studying aspects of diet in dogs, who are our beloved companions and who share our environments, but it's just the tip of the iceberg ... Even if we do eventually find that eating once per day as opposed to more frequently is playing a causal role in these beneficial health outcomes, there are obviously other considerations that might come into play for any individual dog, including their preference, expectations, and quality of life."

Rosalind Arden, who studies canine intelligence at the London School of Economics and Political Science, and was not involved in Bray's study, told Newsweek it was "really interesting, well executed study."

"They found an association between once a day feeding and lower scores on a test that captures some features of a canine dementia, where high scores mean more impairment. The authors don't assert that feeding style causes impairment, but I would consider trying that feeding style on a dog—while keeping an eye out for how it seems to be going.

"As with any new results, confidence in the findings will grow if other studies find similar results. [It is] important to note that the dog dementia scale is owner-report, not a psychometric test—which would have been hard to achieve in such a large dataset.

"Considering benefits from caloric restriction or interval feeding is an intriguing context for the work."