It’s a common semi-humorous observation that dogs and their owners tend to look alike. Unfortunately, one way they resemble each other all too often is in being overweight. With obesity statistics going through the roof for both people and dogs, it’s worth taking a closer look at whether there actually is a link between the weight problems of dogs and their owners–and what might be done about it, for the good of both parties.
In fact, the health community has taken this question quite seriously for a while, and a number of research studies have been conducted to identify the factors that put pets at risk for obesity, the role their owners may have in that risk, and whether understanding the connection might help us identify opportunities to address the obesity epidemic in both people and pets. These studies are interesting for what they can tell us about the contributing causes of overweight in both domestic animals and their human owners. Their findings may even suggest some possible approaches for treating this shared problem.
Research Studies on Obesity in Dogs
When studying the causes of human obesity, genetic risk factors obviously need to be considered for the role they might play when parent and child are both obese. Genetic influence may account for as much as 50 to 90 percent of variance in body mass index (BMI) for people. This makes it more complex to isolate and evaluate behavioral and environmental causes of excess weight in human populations.
Between humans and pets, on the other hand, it is possible to pretty much exclude genetics as a cause for the coincidence of overweight. This makes it possible to focus on the external factors that could be contributing to the shared incidence of overweight in both the people and their animals.
As early as 1970, E. Mason published a study on “Obesity in pet dogs” that found a demonstrable link between obesity in owners and their pets, and subsequent research has confirmed this relationship . Since the amount of food and exercise pets receive depends pretty much entirely on their owners, the relationship between an owner’s attitude and actions and a pet’s weight seems likely to be significant.
Obesity Risk Factors in Dogs
In a study on “Risk Factors for Obesity in Dogs in France,” Laurence Colliard and his colleagues at the Ecole Nationale VÃ©tÃ©rinaire d’Alfort looked at 681 dogs and their owners and gathered information regarding the dogs’ body condition, as reported by both their owners and their veterinarians, and a number of factors about the owners, such as their age, lifestyle, and socio-economic status . They took into consideration a number of potential contributors to obesity in dogs, such as age, gender, breed, and whether they were neutered.
The researchers determined that almost 39 percent of the dogs studied were overweight. The highest risks were associated with increased age, female gender, being neutered, and being a retriever breed. They also found that owners have a strong tendency to misjudge their dogs’ body condition, failing to recognize their weight problems. This represents a special challenge to veterinarians, who are likely to have difficulty convincing many owners that their pets are overweight or at risk for obesity and related health problems.
The Human Risk Factor
The role human denial plays in dog obesity was analyzed in considerable detail by Kienzle et al. in their study “A Comparison of the Feeding Behavior and the Human-Animal Relationship in Owners of Normal and Obese Dogs,” published in The Journal of Nutrition in 1998 . They compared the situations of 60 obese dogs and 60 normal dogs, using questionnaires and personal interviews with the owners to evaluate the human-dog relationships. They found that equally close bonds existed between all the dogs and their owners. However, the owners of obese dogs were more likely to “overhumanize” their pets, in the researchers’ view, as indicated by talking to them more, sharing their beds with them, feeding them more often, and indulging them with kitchen scraps and other food treats.
Kienzle’s research team also noted that people who owned obese dogs were themselves more likely to be obese, to get little exercise, and to have little interest in preventive health care. They treated their dogs essentially the same way they treated themselves: their dogs were not given as much exercise or activity, and their owners took less interest in ensuring that their dogs’ diets were balanced and nutritious. Obese dogs were more prevalent among lower income households.
Overall, Kienzle et al. concluded that the owners of obese dogs tended simply to be extending to their dogs their own lack of concern for health, nutrition and exercise. Instead of exercise, “feeding of the dog was used by the owners as a handy and agreeable form of communication and interaction with their dog.” They recommended that owners be encouraged to reward their dogs with attention and activity rather than food, noting that regular walks and other playful activities would benefit the owners as well as the dogs.
The Role of Exercise
In a study published in Public Health Nutrition in 2009, Nijland et al. confirmed once again that there was a positive correlation between the BMI of overweight owners and their dogs–though not between overweight owners and their cats . They also found that the correlation between the dogs’ BMI and the owners’ decreased or even disappeared once the amount of time the pets and owners spent walking together was taken into account. The same effect was not observed for cats, presumably because the ways cats get exercise does not generally require that their owners participate along with them.
Though their data was not extensive enough for a definitive conclusion, it certainly supports the idea that the amount of time dogs and their owners spend walking together can affect the degree of overweight for both parties, leading Nijland to conclude that “getting a dog with the instruction to walk it regularly might be an effective way to prevent overweight in both the owner and the dog.”
It’s difficult to argue with Kienzle’s rather harsh conclusion that people whose dogs are obese may be transferring to their pets “their own health and eating habits, including a certain laziness and a lack of appreciation of the dog’s nutritional and health requirements.” Even among owners who are not themselves overweight, having an overweight dog seems at the very least to betray a fundamental lack of understanding of the real needs of their animal companions–for attention, occupation, exercise, and a balanced and nutritional diet that will enable them to live longer, happier lives.
1. Mason, E. Obesity in Pet Dogs. Veterinary Record. 86,21:612-616, 1970.
2. Colliard, L., Ancel, J., Benet, J-J., Paragon, B-M., Blanchard, G. Risk Factors for Obesity in Dogs in France. Journal of Nutrition. 136: 1951S-1954S, 2006
3. Kienzle, E., Bergler, R., Mandernach, A. “A Comparison of the Feeding Behavior and the Human-Animal Relationship in Owners of Normal and Obese Dogs. Journal of Nutrition. 128:2779S-2782S, 1998
4. Nijland, M.L., Stam, F. Seidell, J.C., Overweight in dogs, but not in cats, is related to overweight in their owners. Public Health Nutrition, 2009.
About the Author
Matt Ntinos is a biologist and postdoctoral fellow at Washington University School of Medicine and the owner of a beautiful German Shepherd named Hera. Matt is concerned about the obesity epidemic in both humans and dogs, which research shows is affected by similar factors food management, exercise and social factors. He is fascinated by new studies that show how humans and animals can lose weight together. Matt’s website, devoted to reviews of online weight loss plans, offers a Medifast code and Nutrisystem promotion codes, two medically approved diets.