Teens who eat more ultra-processed foods score lower in school

A Spanish study of nearly 800 adolescents reveals that students who consume more ultra-processed foods (UPFs) have significantly lower grades in language, math, and English—highlighting diet quality as a key factor in academic success.

​​​​​​​Study: Investigating the Relationship Between Ultra-Processed Food Consumption and Academic Performance in the Adolescent Population: The EHDLA Study. Image Credit: ESB Professional/Shutterstock.com

In a recent study published in Nutrients, researchers explored whether the consumption of ultra-processed foods (UPFs) could influence academic performance during adolescence, a time known to be critical for growth and development.

Their findings indicate that adolescents who consume more UPFs show poorer academic performance based on multiple indicators, highlighting the importance of improving diets to strengthen educational outcomes.

Background

Adolescence, or the phase of life between childhood and adulthood, is often defined as the time between the ages of 10 and 19 and is critical for brain development, particularly the prefrontal cortex.

During this time, individuals experience changes in the way they experience emotions, think, make choices, and interact with others.

Academic performance during this time is a significant predictor of future opportunities and outcomes. Adolescents have the opportunity to explore several disciplines, participate in educational and other activities, and expand their knowledge base.

This develops their capacity to solve problems and think analytically, while their academic accomplishments boost their psychological well-being by increasing their self-esteem.

Unfortunately, not all adolescents receive the same opportunities, as external factors such as their socioeconomic background are linked to characteristics such as the educational institution they attend and their sleep and dietary patterns.

Previous research suggests that young individuals who consistently eat breakfast, consume less energy-dense food, and follow better diets show better academic performance. Other studies have found a positive association between Mediterranean diet adherence and educational grades.

Poor diets, particularly high levels of UPF intake, are known to have adverse impacts on human health. Still, their consumption has increased rapidly around the world because they are palatable, convenient, and long-lasting.

A Chinese study showed that children between four and seven who frequently consumed UPFs such as candies and sweet baked goods had lower scores for verbal comprehension, but another study in Brazil found no link between the UPF intake of adolescents and their cognitive functioning.

Further study is needed to understand this relationship and design effective interventions to improve adolescent well-being.

About the study

Researchers utilized existing data from a survey that included Spanish adolescents between 12 and 17 and took place in 2021 and 2022. Overall, 788 individuals were included in the final sample, of whom 44.7% were boys, and their parents and guardians provided written consent.

The participants filled out food frequency questionnaires, which included 12 food groups and 45 individual food items. These foods were classified into four levels of processing, namely UPFs, processed foods, products with processed culinary ingredients, and minimally processed or unprocessed foods.

Their academic performance was assessed using their school records, with a focus on English, mathematics, and language evaluations, as well as overall grade point averages (GPA).

Other factors that could influence the relationship between UPF consumption and educational outcomes, including physical activity, sedentary behavior, sleep duration, body mass index (BMI), socioeconomic status, age, and sex, were also collected.

The research team used statistical methods such as descriptive statistics and regression models to analyze the data.

Findings

The survey found that adolescents consumed a median of four UPF servings, equivalent to approximately 240 grams, each week. They scored a median of 6.0 for English, language, and mathematics and had a median GPA of 6.3.

There was a significant negative association between UPF intake and academic performance across all four indicators. The adolescents who consumed the most UPFs showed the poorest academic performance, while those who consumed the least UPFs performed best, indicating that there is a dose-response relationship.

Individual UPF products, sweets, fried foods, beverages, dairy products, and fast foods were all linked to worse academic performance. Notably, sausages, which are also categorized as UPFs, were not correlated with poor educational outcomes. 

Conclusions

This study adds to existing evidence that UPFs may lead to worse academic outcomes for adolescents. The observed relationship could be due to nutritional imbalances caused by a UPF-rich diet, which is high in artificial additives, added sugars, and saturated fats but lacks essential nutrients such as omega-3 fatty acids needed for brain development and cognitive function.

The added sugars in UPFs could also cause fluctuations in blood glucose, increasing fatigue and reducing alertness. Consuming UPFs regularly has also been implicated in poorer sleep quality, decreasing decision-making ability, attention, and memory. Finally, UPFs could also lead to chronic inflammation, which can impair brain function.

While these findings are indicative, the research team notes that they are observational, as the cross-sectional nature of the study precludes causal inference. Since the dietary data is self-reported, findings may be biased due to errors in recall.

Interventions that reduce UPF consumption among adolescents could support their overall development and academic success, with benefits for social and health outcomes.