Prediabetes has become significantly more common among children living with overweight or obesity over the past two decades, even though obesity rates themselves have not increased, according to new research from Finland.
The study, led by researchers at University of Eastern Finland and Tampere University, tracked metabolic health trends among children assessed for overweight or obesity between 2002 and 2020. The findings, published in the International Journal of Obesity, suggest that rising metabolic risk in childhood may not be explained by body weight alone.
Researchers analyzed health data from 602 children ages 6 to 16 who were evaluated in primary or specialized health care settings in Tampere, Finland. A control group of 483 children was drawn from a population-based cohort participating in the Physical Activity and Nutrition in Children study. Across the full study population, 34% of children assessed for overweight or obesity had prediabetes, while 1% had type 2 diabetes. In the control group, 7% had prediabetes and none had type 2 diabetes.
What stood out most was how sharply prediabetes prevalence increased over time. In the early 2000s, about 11% of children with overweight or obesity had prediabetes. By the late 2010s, that figure had risen to 50%. Over the same period, researchers found no significant changes in the prevalence or degree of obesity, body mass index or the presence of other metabolic disorders, suggesting that something beyond weight alone may be driving the trend.
Prediabetes was more common in older children and those further along in puberty. It was also associated with fatty liver disease and acanthosis nigricans, a skin condition often linked to insulin resistance and disturbances in glucose metabolism. These findings point to a broader shift in metabolic health rather than a simple increase in body size.
The only other major change observed during the study period was a substantial rise in maternal overweight. The proportion of mothers with overweight increased from 20% in the early 2000s to 69% by the end of the study window.
“The rise in the prevalence of prediabetes without changes in children’s weight may partly be explained by factors related to pregnancy and the fetal period,” said Hanna Riekki, MD, a researcher at Tampere University.
She added that changes in children’s body composition, physical activity or diet may also play a role, and that further research is needed to better understand these factors.
The researchers emphasized that maternal weight is not the sole explanation and should not be viewed as deterministic. Instead, the findings highlight the possibility that early-life conditions, including those during pregnancy, may influence metabolic health in ways that become visible later in childhood.
“The results show that even if the prevalence or degree of obesity does not change, obesity-related comorbidities may still become more common,” said Professors Kalle Kurppa and Timo Lakka, senior investigators on the study.
Prediabetes increases the risk of developing type 2 diabetes and other cardiometabolic conditions, including fatty liver disease and cardiovascular disease. When metabolic disturbances begin in childhood, they may progress more rapidly and lead to complications earlier in life than conditions that develop in adulthood.
The authors argue that these findings reinforce the importance of screening for metabolic disturbances in children with increased adiposity, rather than relying on body weight alone as an indicator of risk. Early identification could allow for earlier interventions aimed at improving metabolic health during a critical window of development.
Funding and support for this study were provided by the Foundation for Pediatric Research, the Competitive State Research Financing of Tampere University Hospital, the Maire Rossi Foundation, the Maud Kuistila Foundation, the Juho Vainio Foundation, the Finnish Cultural Foundation, the Emil Aaltonen Foundation, the Paulo Foundation, the Orion Research Foundation and the Sigrid Jusélius Foundation. Open access funding was provided by Tampere University, including Tampere University Hospital.