In a groundbreaking study published in the journal Nature Medicine, researchers have unveiled a genetic test that could potentially predict a child’s risk of developing obesity in adulthood.
This could pave the way for early interventions designed to combat the growing obesity epidemic.
The research involved a collaboration of over 600 scientists from around the globe, who analyzed genetic data from more than 5 million individuals, making it the largest and most diverse genetic dataset compiled to date.
Using data from sources like 23andMe, the researchers developed a polygenic risk score that takes into account various genetic variants associated with increased body mass index (BMI) in adulthood.
This score could allow for predictions about a person’s obesity risk as early as age five.
Ruth Loos, a professor at the University of Copenhagen’s Novo Nordisk Foundation Center for Basic Metabolic Research and a co-author of the study, emphasized the importance of intervening during childhood.
Loos highlighted the pressing nature of the findings, particularly as global obesity rates have surged.
According to statistics from the World Health Organization, adult obesity rates have more than doubled since 1990, and adolescent obesity rates have quadrupled.
Currently, about 16% of adults worldwide and over 40% of adults in the United States are classified as obese, according to the Centers for Disease Control and Prevention.
The new genetic test is not the first attempt to assess obesity risk, but Loos and her team demonstrated that it is approximately twice as effective as current assessment methods.
The traditional assessments can account for roughly 8.5% of a person’s risk of high BMI in adulthood, whereas the new polygenic risk score increases that percentage to approximately 17.6%, particularly among individuals with European ancestry.
Dr. Roy Kim, a pediatric endocrinologist at Cleveland Clinic Children’s who was not part of the study, noted that while the new score is a significant advancement, it still leaves much unknown about obesity risk factors.
He explained that over 80% of a person’s risk of obesity can be attributed to factors beyond genetics, including environmental influences, access to nutritious food, and physical activity levels.
However, the effectiveness of the test varies according to genetic background.
The score explained approximately 16% of the obesity risk for East Asian Americans, but only about 2.2% for rural Ugandans.
In the study, around 70% of participants were predominantly of European descent, with 14% identified as Hispanic, about 8% as predominantly East Asian, and just under 5% as predominantly African.
Notably, only 1.5% of the participants were of predominantly South Asian descent.
Loos declared that the new score is still in its infancy and emphasized the necessity for more diverse data, especially from individuals with African ancestry, to enhance the accuracy of the predictive model for a broader population.
She likened the significance of the genetic score to that of high blood pressure in predicting heart disease, stressing that while genetics play a major role, they cannot wholly determine obesity outcomes.
Loos pointed out that genetics are more critical in cases of severe obesity, defined as a BMI over 40.
Identifying genetic risks in childhood and implementing lifestyle changes could notably change the trajectory of obesity development in these individuals.
Research indicates that approximately 55% of children with obesity continue to experience those issues into adolescence, and roughly 80% of those will carry obesity into adulthood.
Dr. Kim highlighted the essential nature of behavioral factors, noting that access to healthy food, opportunities for exercise, and overall knowledge about nutrition play vital roles in obesity risk.
Despite studies showing that genetics can account for up to 80% of an individual’s risk for obesity, lifestyle choices remain profoundly influential.
Kim noted, “Even with the same genetic makeup, people can have different body types.”
In his practice, he emphasizes educating patients about the importance of a balanced diet rich in protein, fruits, and vegetables, while advising against excessive refined carbohydrates.
Dr. Juliana Simonetti, co-director of the Comprehensive Weight Management Program at the University of Utah, has utilized genetic testing with her adult patients for five years.
She believes that understanding a person’s genetic profile can lead to more effective treatment methods for weight management.
Simonetti stated that obesity is not a one-size-fits-all condition.
She assesses genetic factors to determine whether patients struggle with satiety or the sense of feeling full.
Individuals with specific genetic mutations may not feel full despite eating, leading them to have higher weight.
But she stressed that such mutations represent only part of the broader genetic landscape influencing obesity.
Both inherited genes and those not categorized as mutations also significantly determine body weight storage and energy expenditure.
Simonetti also pointed out that genetic testing is beginning to reveal how effectively certain weight loss drugs work in individuals.
However, she cautioned that current findings address only a few out of many genetic variations associated with obesity.
With advancing research, she remains hopeful that a more nuanced understanding of treatment responses will develop.
The study’s findings are a promising step forward but underline the complexity of obesity as an issue influenced by both genetic and lifestyle factors.
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