Genetic-Driven Dieting May Drive Weight Loss in the Future

With New Year's resolutions to hit the gym and eat healthier still top of mind, experts say the next big advance in achieving a healthier weight will be to use an individual's genetic data to customize diets and physical activity plans. According to a review published by a National Institutes of Health working group in the January issue of Obesity, the biggest challenge to realizing "precision weight loss" is the need for better analytical tools to uncover the relationships between genetics, behavior, and intentional change in weight.

"I think within five years, we'll see people start to use a combination of genetic, behavioral, and other sophisticated data to develop individualized weight management plans," said work group lead Molly Bray, Ph.D., a geneticist and professor of nutritional sciences at University of Texas, Austin, in a statement.

Bray envisions that in the future, it will be possible for patients to submit saliva samples for gene sequencing, in combination with wearables to collect information about the patients' environment, diet, activity, and stress. A computer algorithm could then take this information and provide patients with specific recommendations to achieve their target weight.

The review grew out of a workshop convened by the NIH back in 2014 titled "Genes, Behaviors, and Response to Weight Loss Interventions." It identifies both what is genetically known about obesity and body size, as well as needed future directions for research.

Roughly 150 loci have been identified that are associated with obesity and body size. It is estimated that genetics may account for about half of variance in individuals' body size, while environmental influences, such as diet and activity, account for the other half. But, despite this evidence for a genetic component to regulation of body mass/composition, only a limited number of genes have been identified that are tied to body weight change in response to changes in the environment, the review found. Said another way, experts believe that the genetic determinants of weight change response (genes tied to weight loss, maintenance, and/or regain) may differ from known genes associated with BMI and obesity.

To address these gaps and enable precision medicine in behavioral weight loss to become a reality, the work group offers some future directions for research.

• Genome-wide studies and randomized controlled trials can identify novel genetic loci for intentional weight loss, maintenance, and regain. This will aid in identifying baseline genetic characteristics that will permit tailored treatment guidelines (i.e., identify and target subgroups within obese populations genetically prone to respond well to a specific weight loss intervention).

• Assess whether these genetic discoveries and targeted interventions can be implemented in a clinical setting to motivate behavior change and adherence to weight loss interventions.

"To advance the field of precision weight loss, the combination of an individual's genotype, along with the unique underlying pathophysiology it suggests, should be used to develop dietary and physical activity recommendations that target the metabolic derangements specific to each person," writes Bray and her colleagues. "The success of such interventions would rely not only on an understanding of the pathophysiological mechanisms linking genotype and weight, but also on the ability to communicate a personalized strategy to patients and motivate behavior change."

Takeaway: While still several years away, experts are optimistic that future improved understanding of genes tied to weight loss, maintenance, and regain will be identified and exploited to target intervention efforts.