Study finds no metabolic danger from ultra-processed foods

By Dr. Sanchari Sinha Dutta, Ph.D.Reviewed by Lauren HardakerJul 9 2025

Your overall diet matters more than you think. A major European study challenges assumptions about ultra-processed foods, revealing that although they harm diet quality, there is no clear link to metabolic syndrome.

Study: Ultra-Processed Foods Consumption and Metabolic Syndrome in European Children, Adolescents, and Adults: Results from the I.Family Study. Image credit: Rimma Bondarenko/Shutterstock.com

A recent study involving a large group of European children, adolescents, and adults reveals that ultra-processed food intake does not appear to be significantly associated with the prevalence of metabolic syndrome, despite negatively affecting diet quality. The findings are published in the journal Nutrients.

Background

The consumption of highly processed, ready-to-eat foods, also known as ultra-processed foods, has considerably increased worldwide in recent decades, replacing healthy dietary habits of consuming traditional foods and freshly prepared meals. Various factors, including socio-cultural changes, industrialization, technological advancements, and the globalization of food production, have triggered this transition.

Ultra-processed foods contain high amounts of preservatives, flavors, additives, and other substances not commonly found in home-cooked foods. These ingredients are used to increase palatability, shelf life, and convenience of preparation.

The nutritional composition of ultra-processed foods is characterized by high levels of saturated fats, salt, sugar, and other energy-dense substances and low levels of proteins, dietary fibers, and essential micronutrients. This low-quality nutritional profile substantially contributes to health adversities associated with ultra-processed food intake, including cardiovascular disease, type 2 diabetes, and obesity.

The most profound increase in ultra-processed food intake has been observed in Western countries, including the USA, Canada, and the UK. Recent findings from the European multicenter I.Family study reveal that ultra-processed foods contribute approximately 50% of Europeans' total dietary energy intake, particularly in children and adolescents.

In the current study, researchers analyzed data from the I.Family study to systematically evaluate the impact of ultra-processed food intake on metabolic health among European children, adolescents, and adults.

The study

The study used data from 2285 participants of the I.Family study, which was conducted between 2013 and 2014 across eight European countries. Among participants, 147 were children, 645 were adolescents, and 1493 were adults.

The ultra-processed food intake of participants was assessed using 24-hour dietary recall data. The consumption levels were divided into age- and sex-specific quintiles based on the relative energy contribution of these foods.

For metabolic health assessment, metabolic syndrome scores were calculated using standardized methods. In children and adolescents, age- and sex-standardized z-scores for components such as waist circumference, blood pressure, HDL cholesterol, and insulin resistance were summed into a continuous score. In adults, metabolic syndrome was defined categorically based on internationally recognized clinical criteria.

Metabolic syndrome is a group of health disorders, including central obesity, high blood glucose, abnormal lipid profile, and high blood pressure. With steadily increasing prevalence, metabolic syndrome has become a significant public health concern worldwide, paralleling the epidemic of overweight and obesity.   

Key findings

The study analysis revealed that ultra-processed foods contributed 48% of the total energy intake in children, 47% in adolescents, and 40% in adults. Across all age groups, higher intake of ultra-processed food was significantly associated with higher intakes of total energy, sugar, and saturated fat, and a lower percentage of total energy intake from proteins and dietary fibers, reinforcing poor diet quality of these foods.

The study found that ultra-processed food intake was not significantly associated with metabolic syndrome or its components among European children, adolescents, and adults after adjusting for relevant factors such as BMI, education, income, and total energy intake. While some trends, such as increased prevalence of high metabolic scores in children with the highest UPF intake, were observed, these associations were not statistically significant.

Study significance

The study reports that ultra-processed food intake does not significantly increase the prevalence of metabolic syndrome in a heterogeneous European population, varying in age and socio-cultural characteristics. However, it is important to note that this was a cross-sectional study, which assesses association at one point in time and does not allow conclusions about causality or incidence over time.

Most previous studies in this field have reported adverse health effects of consuming ultra-processed foods, with some reporting an increased risk of metabolic syndrome. The inconsistency between prior and current study findings may be due to the differences in dietary assessment tools, cultural dietary patterns, follow-up duration, and the definition and measurement of metabolic syndrome. Differences in how ultra-processed foods are classified and how outcomes are measured may also contribute to varied study results.

The study finds a link between a higher intake of ultra-processed food and lower diet quality, highlighting the need for public health strategies that primarily focus on reducing the intake of ultra-processed foods and improving dietary patterns, particularly among younger populations. The researchers recommend that nutritional education promote fresh and minimally processed foods intake and emphasize the potential long-term health risks associated with ultra-processed foods. 

The study also finds that intake of ultra-processed foods reduces with age, highlighting the importance of targeting dietary interventions across different age groups.

The study excluded a large proportion of I.Family study participants who lacked information about any metabolic risk factors, had an implausible energy intake, or did not meet the desired fasting requirements. Although the difference in ultra-processed food intake was modest between included and excluded participants, this selection process may have affected the representativeness of the study population and could limit the generalizability of findings.

Due to the reduction in the sample size, the study could not consider some of the major confounding factors, such as physical activity, genetic predisposition, and environmental factors. These confounders can affect the association between ultra-processed food intake and the risk of metabolic syndrome. Future studies should consider these confounders to understand the impact of these foods on metabolic health more conclusively. The effects reported for the association between ultra-processed food intake and metabolic syndrome were minimal, suggesting that even if a relationship exists, it may be weak or influenced by other unmeasured factors.

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