It appears that both humans and Labradors share certain characteristics, including a tendency to gain weight if they possess a specific gene variant. This discovery was made by researchers in the UK, who identified gene variants associated with obesity in British Labrador Retrievers. Interestingly, they found that the same gene variants are also linked to excessive weight gain in humans.

The study, published on March 6 in the journal Science, reveals that while the news may seem bleak, there is a silver lining. Both Labradors and humans with the gene variants can prevent weight gain by adhering to a strict diet and exercise routine. As explained by lead author Eleanor Raffan, a veterinary surgeon and researcher at the University of Cambridge, “By studying dogs, we could measure their desire for food separately to the control owners exerted over their dog’s diet and exercise. In human studies, it’s harder to study how genetically driven appetite requires greater willpower to remain slim, as both are affecting the one person.”

The research team collected data from 241 Labradors, measuring their body fat, determining their “greediness” levels, and collecting saliva samples. By comparing each dog’s body fat to its genetic information, they were able to pinpoint the genetic components most likely linked to canine obesity. The team discovered that dogs with a particular variant of the DENND1B gene, known as rs24430444, had approximately 8% more body fat than those without it.

Co-author Natalie Wallis, a researcher in the University of Cambridge’s department of physiology, development, and neuroscience, noted that “We measured how much dogs pestered their owners for food and whether they were fussy eaters. Dogs at high genetic risk of obesity [carrying the gene variants linked to obesity] showed signs of having higher appetite, as has also been shown for people at high genetic risk of obesity.”

The study also revealed that the DENND1B gene, along with four other genes linked to canine obesity, are implicated in human obesity. The DENND1B gene plays a role in the brain’s leptin melanocortin pathway, which regulates the body’s energy balance. However, as biologist Alyce McClellan from the University of Cambridge pointed out, “these genes are not immediately obvious targets for weight-loss drugs, because they control other key biological processes in the body that should not be interfered with.”

Despite this, the team found that owners who imposed a strict eating and exercise regimen on dogs carrying the DENND1B variant were able to prevent obesity in their pets, although it required significantly more effort. As Raffan explained, “Studying the dogs showed us something really powerful: owners of slim dogs are not morally superior. The same is true of slim people. If you have a high genetic risk of obesity, then when there’s lots of food available you’re prone to overeating and gaining weight unless you put a huge effort into not doing so.”

In other words, humans with the DENND1B variant linked to obesity are not predestined to gain weight, but it will be much harder for them to keep it off compared to others due to their genetic predisposition. Raffan added, “This work shows how similar dogs are to humans genetically. Studying the dogs meant we had reason to focus on this particular gene, which has led to a big advance in understanding how our own brain controls our eating behaviour and energy use.”

Ultimately, the next time you scold your Lab for begging, remember that you might have more in common with them than you think!