High BMI in adolescence may speed up biological aging

A recent study found that a high adolescent body mass index (BMI) may be linked to accelerated biological aging in adulthood. The Faculty of Sport and Health Sciences at the University of Jyväskylä, Finland, reported these findings, suggesting that adolescents with a higher BMI may age biologically faster than others.

The researchers assessed participants’ biological age and examined whether adolescent BMI was associated with the rate of biological aging.

“Our findings suggest that genetic predisposition to high body mass index is associated with accelerated biological aging,” says Doctoral Researcher Anni Pitkänen. “Part of this association may be explained by the fact that the inherited predisposition is reflected in higher adolescent BMI.”

Evidence suggesting a causal link: The researchers also used a method known as Mendelian randomization to investigate whether adolescent BMI causally affects biological aging.

The results indicate that higher adolescent BMI may be causally associated with accelerated biological aging.

“Adolescents with both a genetic predisposition to high BMI and a high BMI may experience accelerated biological aging,” Pitkänen explains. “This could increase their risk of developing obesity-related diseases later in life, as well as premature death.”

The observed associations may partly reflect adult BMI, as higher adolescent BMI often continues into adulthood, and obesity-related diseases typically develop over many years.

“The results of our study emphasize the importance of preventing overweight and obesity throughout the life course,” Pitkänen notes.

Biological age measured using epigenetic clocks: Biological aging does not always progress at the same rate as chronological age. Faster biological aging has been linked to an increased risk of chronic diseases and premature death.

Measuring biological aging may help identify health risks associated with overweight and obesity before they become apparent in clinical assessments.

In the study, participants’ biological age was assessed using DNA methylation-based epigenetic clocks, computational models developed using machine-learning methods.

The study included participants from the Cardiovascular Risk in Young Finns Study. Participants’ BMI was measured during adolescence, between the ages of 9 and 18. The participants have been followed for approximately 40 years, with information on their health and lifestyle collected at multiple time points throughout the study. Genetic predisposition to higher BMI was assessed using a polygenic risk score that summarizes the effects of hundreds of genetic variants associated with body mass index.

This study is the first publication arising from Anni Pitkänen’s doctoral dissertation, which examines body weight trajectories from childhood to adulthood and their links to genetics, environmental influences and biological aging.

By the University of Jyväskylä for Newswise. The Gayly online. 10/22/26 @ 6:34 p.m. CST.