Higher Ultra-Processed Food Intake Linked to Increased Prediabetes Risk in Young Adults

Ultra-processed foods (UPF), such as fast food, sugary snacks, and packaged convenience items, make up more than half of the calories consumed in the US. Their health risks, such as increased rates of type 2 diabetes (T2D) and other chronic diseases, are known in adults; however, their impact on children and adolescents is less understood.^1,2

In a new study conducted by researchers from the Keck School of Medicine of USC, investigators explored how consuming UPF impacted the body’s ability to process glucose, which is a key indicator of diabetes risk. The study authors, who published their findings in the journal Nutrition and Metabolism, noted that an increase in UPF intake was linked with a higher risk for prediabetes.^1,2

"Our findings show that even modest increases in UPF intake can disrupt glucose regulation in young adults at risk for obesity. These results point to diet as a modifiable driver of early metabolic disease and an urgent target for prevention strategies among young people,” Vaia Lida Chatzi, MD, PhD, a professor of population and public health sciences and pediatrics and director of the Southern California Superfund Research and Training Program for PFAS Assessment, Remediation and Prevention (ShARP) Center at the Keck School of Medicine, and the study’s senior author, said in a news release.²

Prediabetes Link With Ultra-Processed Foods

Prediabetes has become more common in young adults, increasing the risk for early-onset T2D with an estimated prevalence of 17.9 per 100,000 in US youth under the age of 20 years. A T2D diagnosis often impacts an individual’s quality of life, leads to comorbidities, and increases mortality risk. Early-onset T2D in young adults is also linked to greater long-term health complications compared to cases that develop later in life. Obesity, along with poor diet and other lifestyle factors, significantly increases the risk for both prediabetes and T2D. The study authors noted since these conditions share common, modifiable risk factors, evaluating and improving diet is essential for their prevention and management.¹

Limiting intake of UPFs, which are foods that undergo multiple industrial processes before consumption, is among these diet changes. Common examples include soft drinks, packaged snacks, margarine, and sausages. These foods are typically high in sugar, salt, and unhealthy fats, but are low in essential nutrients.¹

Previous research has shown that high UPF consumption is linked to poor diet quality and a greater risk of chronic diseases like T2D, hypertension, and cardiovascular disease, highlighting the importance of limiting UPF intake during childhood and adolescence.¹

"Young adulthood is a critical window for shaping long-term health,” Chatzi said. “By focusing on young adults, we have an opportunity to intervene early, before prediabetes and other risk factors become lifelong conditions.”²

How Does UPF Impact Glucose?

Researchers conducted a cohort study based on the Metabolic and Asthma Incidence Research (Meta-AIR) study, part of the broader Southern California Children’s Health Study, to examine associations between UPF consumption, prediabetes, and related biomarkers in youth.^1,2

A total of 85 young adults aged 17 to 22 years were included and were required to attend a baseline visit between 2014 and 2018, along with a follow-up visit 4 years later, where they shared everything they had eaten on one recent weekday and one recent weekend. Researchers categorized foods as ultra-processed or not and measured what percentage of each participant’s daily calories came from UPFs. They then analyzed blood samples before and after a sugary drink to assess insulin response and prediabetes risk.^1,2

The findings indicated a 10% increase in UPF intake was linked to a 64% higher risk of prediabetes, a 56% higher risk of impaired glucose regulation, and elevated insulin levels. This suggests that eating more UPFs was linked to insulin resistance and associated with a high risk for prediabetes.^1,2

“These findings indicate that UPF consumption increases the risk for prediabetes and type 2 diabetes among young adults—and that limiting consumption of those foods can help prevent disease,” Yiping Li, a doctoral student in quantitative biomedical sciences at Dartmouth College who previously worked as a researcher at the Keck School of Medicine and the study’s first author, said in the news release.²

REFERENCES

1. Li, Y., Costello, E., Rock, S. et al. Ultra-processed food intake is associated with altered glucose homeostasis in young adults with a history of overweight or obesity: a longitudinal study. Nutr Metab (Lond) 22, 135 (2025). https://doi.org/10.1186/s12986-025-01036-6

2. USC study links ultra-processed food intake to prediabetes in young adults. EurekAlert! News release. November 10, 2025. Accessed November 13, 2025. https://www.eurekalert.org/news-releases/1105461