A new longitudinal study shows that rising ultra-processed food intake in young adults with a history of overweight or obesity sharply increases prediabetes risk. This shows how everyday eating habits may quietly push glucose regulation toward dangerous territory.
Study: Ultra-processed food intake is associated with altered glucose homeostasis in young adults with a history of overweight or obesity: a longitudinal study. Image credit: Al More/Shutterstock.com
A recent study published in the journal Nutrition and Metabolism finds that ultra-processed food intake may increase prediabetes and risk factors associated with later development of type 2 diabetes in young adults with a history of overweight or obesity.
The rise of ultra-processed diets
Prediabetes has become a significant public health concern among young adults, as this clinical condition can increase the risk of early-onset type 2 diabetes. Type 2 diabetes is a known risk factor for many chronic diseases and premature mortality. In the U.S, its incidence is estimated to be 17.9 per 100,000 young individuals.
Obesity is a major risk factor for prediabetes and type 2 diabetes. Unhealthy lifestyle factors, including an unhealthy diet and physical inactivity, are considered major modifiable risk factors for all these metabolic diseases.
Ultra-processed foods, including soft drinks, packaged snacks, margarine, and sausages, are calorie-dense food items that contain high amounts of salt, sugar, and unhealthy fats, as well as low amounts of dietary fiber and essential nutrients.
In the U.S, more than half of the total dietary energy intake is composed of ultra-processed foods, which are known to increase the risk of cardiometabolic diseases. Many studies have linked ultra-processed food intake with obesity and diabetes risk among adults. However, only a few studies have investigated the health effects of ultra-processed foods in children and adolescents, producing mixed results.
Given the potential link between prediabetes, type 2 diabetes, and obesity, and the presence of shared risk factors, University of Southern California researchers, together with their collaborators, assessed whether ultra-processed food intake increases the risk of diabetes in young adults with a history of overweight or obesity.
Measuring diet and metabolism
The study included a total of 85 young adults aged 17 to 22 years who had a history of overweight or obesity in their adolescence. The participants, who had previously participated in the Children’s Health Study in Southern California, were enrolled between 2014 and 2018 and returned for a second visit between 2020 and 2022 (follow-up visit).
They completed two 24-hour dietary recalls for dietary assessment and estimation of ultra-processed food intake.
Glucose homeostasis of participants was assessed through glucose tolerance test, glycated hemoglobin (a measure of glycemic control) level, and insulin resistance.
How UPFs affected health
The study analysis revealed that a 10-percentage point increase in ultra-processed food intake over a period of four years is associated with a 51 % higher risk of developing prediabetes and a 158 % higher risk of impaired glucose tolerance in young adults with a history of overweight or obesity.
The increase in ultra-processed food intake between baseline and follow-up visits was associated with a significant rise in insulin resistance and a positive, albeit non-significant, correlation with higher body mass index (BMI), body fat percentage, and fat mass.
Implications for young adults
The study highlights the adverse impact of ultra-processed food intake on the development of prediabetes and on metabolic risk factors that may contribute to future type-2 diabetes, among young adults with a history of overweight or obesity.
The study focuses on youth populations that have recently reached a physically mature stage and are more likely to undergo significant lifestyle changes that can potentially contribute to metabolic disorders. The study findings, therefore, have significant public health relevance.
Insulin resistance and pancreatic beta-cell dysfunction are two major hallmarks of type 2 diabetes. This study finds a significant association between higher ultra-processed food intake and increased insulin resistance, highlighting a possible mechanism through which unhealthy diets can influence the early physiological changes associated with type 2 diabetes.
The study finds a positive, though non-significant, association between higher intake of ultra-processed foods and obesity-related body composition measurements, suggesting that reducing intake of these unhealthy foods can be beneficial for both diabetes and weight management.
Ultra-processed foods contain high amounts of salt, sugar, and saturated or trans fat, which can significantly increase the risk of metabolic diseases. Existing evidence indicates that all these food components are associated with the development of obesity and diabetes in adults. Studies conducted on children and adolescents indicate that limiting added sugar intake can reduce the risk of various chronic diseases.
All these findings, together with the current study findings, suggest that food components commonly found in ultra-processed foods can contribute to overweight or obesity, which in turn can potentially increase the risk of type 2 diabetes. These food components can be considered as relevant targets for public health interventions.
Due to the small sample size, the study lacks sufficient statistical power to detect associations between ultra-processed food intake and specific important outcomes. Further large-scale studies are needed to ascertain whether these foods directly affect pancreatic beta-cell functions.
Furthermore, the study involves young adults with a history of overweight or obesity in their adolescence, which may restrict the generalizability of its findings to other populations.
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