Consumer gene testing company 23andMe is launching a large online study on the relationship between genetics and weight loss behaviors. Drawing volunteer subjects from its existing customers, the company will investigate three different weight loss strategies in a study that hopes to recruit 100,000 participants.

"This is to my knowledge the first example of a genome-wide association study for behavioral weight loss that is being done," Dr. Liana Del Gobbo, lead scientist on the study, told MobiHealthNews. "In the past, prior investigations were candidate gene studies. They relied on single snips or single genetic variants that were drawn from the literature. And often these snips didn’t replicate."

After recruitment closes on January 8th, the study will begin a 12 week active intervention in three groups, each of which will have educational content delivered to them via email and a web portal. One group will be instructed to follow a high-fat low-carb diet, one will follow a high-fiber diet, and one group will be focused on more strenuous physical activity (though all three groups will be encouraged to increase physical activity). After the 12-week active intervention, 23andMe will follow up at six and 12 months.

"We’re going to be measuring weight loss and we’re asking participants about all sorts of other things," Del Gobbo said. "What types of foods they like to eat. We’ll be asking them about their diet habits as they change, physical activity, how they’re feeling about the intervention, their mood, their hunger level throughout the course of the intervention. We hope to learn quite a bit about the predictors of successful weight loss. Not just genetic predictors, but even non-genetic predictors, whether it’s a matter of motivation or aligning your diet with foods that appeal to you, we’re going to try to uncover what those predictors are."

While participants in the study don't receive monetary compensation, they do receive weight loss tips as well as some of the learnings of the study down the road. 23andMe may seek publication for the results of the trial, but the company also hopes the study will allow it to eventually offer weight loss-related reports.

"Eventually if we make progress in this direction we’ll be able to say to people, based on your genomics and what you’ve told us about your demographics, your food preferences, all sorts of other predictors, you might do a little better on this diet versus that other diet, Del Gobbo said. "What we’re doing is trying to work toward more personalized lifestyle prescriptions. This is something folks are excited about because it’s challenging. We’ve been in a one-size-fits-all era for a long time in terms of diet and physical activity, so what we’d like to try to do is move toward more targeted recomendations that are more personalized for individuals."

This is the second effort 23andMe has made to use its access to consumer genomes for research. The company launched a smaller study focused on sleep in the fall, which was more of a proof of concept. The company is also working with the Milken Institute on a study of people with depression and bipolar disorders.