Can a Genetic Test Help You Reach Your Weight-Loss Goals?

Genetic testing is all the rage, yet there are real questions about whether the technology is really worth it. One of the more tantalizing genetic possibilities: Could your genes suggest the right weight-loss approach for you? That’s what a new study published in the American Journal of Clinical Nutrition suggests.

The researchers looked at 683 men and women ages 18 to 73 from the Food4Me trial, a U.K.-based trial that delivers personalized nutrition and support via the Internet to adults. All the participants were screened for the FTO genetic variation, a trait that’s associated with weight gain. One group was told that they carried this variation, and they received personalized nutrition guidance. In previous research, people who carry the trait are particularly susceptible to saturated fats, benefit from increasing their intake of healthy omega-3 fats (the kind in fish and walnuts, for example), and respond well to exercise.

While the differences between the groups were small—the FTO group lost about a half-pound more and trimmed an additional inch of their waistlines compared to a control group after six months—the researchers were nonetheless enthusiastic about the results. “We think that personalized (nutrition) advice is more effective because it engages each individual better and motivates them to make specific behavioral changes and to sustain those changes,” says study author John C. Mathers, director of the Human Nutrition Research Centre at Newcastle University.

Getting tested for this genetic susceptibility probably isn’t worth the advantages suggested by these results. In fact, past research indicates genetic status as a whole may not make a major difference in weight loss. Mathers points to a larger analysis of data from eight major trials involving nearly 10,000 people published in BMJ in 2016. The results in a nutshell: “We found that FTO [gene] status did not affect weight loss,” he says.

One other positive takeaway from Mathers: “We think this is good news since it suggests that even if the genetic variation made the person a bit heavier, it would not be a barrier to losing weight,” he says. “Genetics matters but not as much as many people assume,” he says. Translation: if you’re overweight, it may not be your genes preventing you from losing it.

The bottom line: Your lifestyle matters more. The diet you eat every day makes a bigger difference in your weight, says Mathers. If you’re overweight and want to lose pounds, the advice to eat fewer fatty and sugary foods and more fruits and veggies still stands, he says. “Most people gain weight gradually over many months and years. Weight loss can take a while so patience and determination are keys to success,” Mathers adds. Plateaued? Here are 17 ways to start losing again.