A headline in the Daily Mail shouted “Why a Dog Is an Obese Child’s Best Friend!” The article described the results of a 2008 study in which children who walked with dogs were 50 percent less likely to be obese than other kids. One in three American children are either overweight or obese, so the idea that dogs will help fight the

Witthaya Phonsawat/123RF
Source: Witthaya Phonsawat/123RF

epidemic of childhood obesity needs to be taken seriously. And the notion that playing with pets burns off calories makes sense. It would certainly be nice to think that puppies will help get our kids off their butts and wean them from their video game and Facebook addictions. But is it true? Here are the results of four new studies that answer this question.

Do Kids With Dogs Get More Exercise?

The idea the living with a dog will keep kids from getting fat is based on the assumption that dogs motivate children to be more physically active. Dr. Carrie Westgarth of the University of Liverpool and her colleagues investigated whether this was actually the case. (Full text here.)They analysed data gathered as part of an ongoing longitudinal study of child and adolescent development in 14,500 families in the Great Britain. Westgarth’s research on the impact of pets on exercise involved over 2,000 children between the ages of 7 and 18.  During data collection periods, each kid was asked to wear a device called an accelerometer that measures human activity levels for at least 10 hours a day for a week. About two-thirds of the children were living with a dog when they were tested.

The researchers found….

  • As the children entered adolescence, they tended to walk their dogs more.
  • But, in reality, not many kids walked their dogs regularly. Indeed, fewer than 8% of the teens said they walked their dog every day.
  • Most importantly, the accelerometer results showed that children and adolescents who lived with dogs did not get any more daily exercise (defined as “moderate to vigorous physical activity”) than kids who did not live with dogs.

So, at least in the UK, kids and teens do not spend much time walking the family pet. Nor does interacting with dogs increase their general activity levels. As the researchers bluntly concluded, “This study provides no evidence to support a relationship between adolescent dog ownership and physical activity.”

Does Dog Walking Reduce Obesity in Teens?

In a 2016 paper published in the journal Preventive Medicine (full text), a team headed by Jessa Engleberg of the University of California at San Diego examined the impact of dog walking on activity levels and obesity in adolescents.  In their study, nearly 1,000 adolescents between the ages of 12 and 17 living in Seattle and Baltimore wore accelerometers for a week. Half of the kids lived with dogs, and 300 of these said they walked their dog at least one day a week. In addition to measuring activity levels, the California researchers also examined the impact of dogs on the teens’ body-mass indexes (BMI).

They found….

  • Teens who walked their dogs did have higher amounts of physical activity than adolescents without dogs or teens with dogs that they did not walk.  The bad news is that while the difference between the groups in exercise was “statistically significant,” it was actually very small. Indeed, the researchers calculated that each day of dog walking added less than two minutes of
    Graph by Hal Herzog
    Source: Graph by Hal Herzog

    exercise a day to a teen’s level of physical activity.

  • As shown in this graph, neither owning a dog nor walking a dog had any impact on the body-mass index of the teenagers. (Note: the graph shows age-adjusted BMI percentiles.)

Do children who live with dogs weigh less than no-dog kids?

The third study was published in the journal Pediatric Obesity (full text here) and, like the first study, it was led by Carrie Westgarth of the University of Liverpool. The study was simple. About 1,000 nine and ten year-old children who were part of an ongoing study of the health and fitness of children living in Liverpool were the subjects. The children were asked whether they currently had pets and, if they had a family dog, how often they walked with it.  

The researchers found…

  • Graph by Hal Herzog
    Source: Graph by Hal Herzog

    Living with a dog had absolutely no impact on the percentage of children who were overweight or obese. 

  • And frequency of dog-walking did not have any effect at all on the children’s body-mass index.

The researchers concluded: “We found little evidence to support that children who live with, or walk with, dogs are any fitter or less likely to be obese than those who do not.”

Do children who are highly attached to their dogs weigh less and spend few hours staring at TV and computer screens?

A potential criticism of the three studies described above is that they did not examine how attached the kids were to their dogs.While a lot of children deeply love the family pet, this not certainly true of all kids. Thus it is possible that children who are devoted to their pets actually do get more exercise and are less likely to be overweight or obese than kids who don’t interact much with their dog. 

This hypothesis was recently tested by Anne Gadomski and a research team from the Research Institute of the Bassett Medical Center. In a previous study of the impact of pets on over 600 children (the average age was 6 years old), the 360 children who lived with dogs did not weigh any less or spend fewer hours watching television or playing video games than kids without dogs.  The children in the study, however, were also given a scale which measured how attached they were to their pets. While these results were not included in the original paper, they were recently published in the journal Pediatric Obesity.

The results showed…

  • Not surprisingly, kids who were more attached to their dog spent more time actively playing with their pet.
  • However, children who spent a lot of time playing with their dog did not weigh less or have less “screen time” than kids who rarely played with the family pet.
  • And, kids who were highly attached to their pets did not have lower body mass indexes that children who were not attached to the dogs. Nor were they less likely to be overweight or obese.

Can A Dog Be An Obese Child’s Best Friend?

These four studies were all published within the last 18 months, and they all had large numbers of subjects. The big samples mean that if there was an effect of dogs on children’s weight or exercise levels, it would almost certainly have been detected. More importantly, even though they were conducted in two countries by three different research teams, a consistent pattern of results emerged. 

First, children and teenagers who live with dogs are no more physically active (or, at best, only slightly more physically active) than children who do not live with dogs. Second, there was not a shred of evidence in any of the studies that living with a dog had any effect on a child chances of being overweight or obese. And this finding was true even among children who were highly attached to their pets.

The bottom line is that the headline in the Daily Mail is right – a dog just might be an obese child’s best friend. But it is not because dogs help kids lose weight.

* * * * * 

Hal Herzog is Professor Emeritus of Psychology at Western Carolina University, and the author of Some We Love, Some We Hate, Some We Eat: Why It’s So Hard To Think Straight About Animals.

References

Engelberg, J. K., Carlson, J. A., Conway, T. L., Cain, K. L., Saelens, B. E., Glanz, K., ... & Sallis, J. F. (2016). Dog walking among adolescents: Correlates and contribution to physical activity. Preventive medicine, 82, 65-72.

Gadomski, A. M., Scribani, M. B., Krupa, N., & Jenkins, P. (2016). Pet dogs and child physical activity: the role of child–dog attachment. Pediatric obesity.

Westgarth, C., Boddy, L. M., Stratton, G., German, A. J., Gaskell, R. M., Coyne, K. P., ... & Dawson, S. (2016). The association between dog ownership or dog walking and fitness or weight status in childhood. Pediatric Obesity.

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