A new genetic test may be able to predict obesity in early childhood. What to know

USA Today

23-07-2025

More than 2 out of 5 adults in the U.S. are considered obese, according to the Centers for Disease Control and Prevention. But what if there was a way to test children to find out if they're at higher risk for contracting the chronic condition while still having time to change their lifestyle?
In a study published July 21 in the journal Nature Medicine, more than 600 scientists from 500 institutions worldwide compiled genetic data from more than 5 million people. Using data collected by The Genetic Investigation of ANthropometric Traits (GIANT) consortium – an international collaboration of human genetics researchers and 23andMe – a genetic measure known as polygenic risk scores (PGS) was developed to help identify children at higher risk of developing obesity in adulthood.
Obesity is a serious, common and costly chronic condition characterized by excessive body fat, often defined as a Body Mass Index (BMI) of 30 or greater. The American Medical Association considers it a significant public health concern, as it increases the risk of numerous conditions, including diabetes and heart disease.
What does the study say?
Researchers developed ancestry-specific and multi-ancestry polygenic risk scores and found they were about twice as effective as the risk assessments doctors currently use. For people with European ancestry, the newly developed risk score accounted for about 17.6% of a person's risk of developing a high BMI in adulthood.
About 70% of participants whose genetic data was compiled in the study had predominantly European ancestry, 14.4% had Hispanic ethnicity with typically mixed ancestries, 8.4% had predominantly East Asian ancestry, 4.6% had predominantly African ancestry and 1.5% were of predominantly South Asian origin, according to the research.
Ruth Loos, a co-author of the study, is a professor at the Novo Nordisk Foundation Center for Basic Metabolic Research at the University of Copenhagen. In an interview with NBC News, she explained, 'Obesity is not only about genetics, so genetics alone can never accurately predict obesity.'
'For the general obesity that we see all over the world, we need other factors, such as lifestyle, that need to be part of the predictions,' added Loos.
Obesity increases the risk of nearly 200 diseases and can cause serious health conditions like asthma, strokes, Type 2 diabetes and some types of cancers. It was a risk factor in 3.7 million deaths in 2021.
Globally, obesity in adults has more than doubled since 1990, with adolescent rates quadrupling, the World Health Organization reported.
How can communities address obesity?
Ensuring access to healthy foods, safe places for physical activity, stigma-free obesity prevention and treatment programs, and evidence-based health care services such as medication and surgery are examples of how to address and prevent obesity, according to the CDC.
Director of the CDC's National Center for Chronic Disease Prevention and Health Promotion, Karen Hacker previously told USA TODAY that there is no singular approach to addressing the health concern.
'Obesity is a disease caused by many factors, including eating patterns, physical activity levels, sleep routines, genetics and certain medications. This means that there is no one-size-fits-all approach, Hacker said.
'However, we know the key strategies that work include addressing the underlying social determinants of health, such as access to health care, healthy and affordable food and safe places for physical activity,' Hacker added.