The key to weight loss could come down to a combination of 14 “skinny genes,” a recent study says.

People with these genes dropped twice as much weight through regular exercise compared to those without the genes, researchers found.

Those with the most of these genetic markers lost up to 11 pounds following eight weeks of running, compared to a little more than 4 pounds for those who didn’t get the same genetic boost.

“This study highlighted some important genes associated with taking inches off the jeans, but it’s important to remember that the genes will do nothing without exercise and lifestyle changes as they are all interlinked,” lead researcher Henry Chung, a lecturer with the University of Essex School of Sport, Rehabilitation and Exercise Sciences in the U.K., said in a news release. 

“Without intervention, they won’t show their true potential and then it doesn’t matter what genes you have,” he continued.

For the study, researchers recruited 38 people ages 20 to 40. About half were asked to run 20 to 30 minutes three times a week, while maintaining all their usual diet and lifestyle habits. The rest served as a control group.

Results show that one specific gene, called PPARCG1A, was most key to weight loss. The gene is involved in energy metabolism and was present in participants who lost the most weight, researchers noted.

The other “skinny” genes are associated with diet, fat storage, metabolism, intelligence and psychological conditions, researchers said.

About 62% of weight loss in the study was linked to genes, and 37% to exercise and lifestyle factors, researchers concluded.

Chung said doctors might someday be able to specifically tailor exercise and diet plans to a person based on their genes.

“If we can better understand someone’s specific genetic profile, hopefully, this will translate to better and more successful interventions for improving health outcomes,” Chung said.

However, he also noted that exercise is beneficial for everyone, not just those blessed with the right genes.

“Away from weight loss exercise has so many benefits – ranging from mental health to cardiovascular fitness – so I’d advise everyone to keep on training even if they aren’t seeing the difference on the scales,” Chung said.

The new study appears in the journal Research Quarterly for Exercise and Sport.