Ultra-processed food linked to weight gain and lower well-being in adolescents

New research examines the impact of ultra-processed food, screen time, and maternal education on weight and well-being in adolescents.

Study: Ultra-Processed Food Consumption and Its Association with Risk of Obesity, Sedentary Behaviors, and Well-Being in Adolescents. Image Credit: KatMoys/Shutterstock.com

In a recent study published in Nutrients, a group of researchers compared ultra-processed food (UPF) consumption, sedentary behaviors, and well-being between adolescent boys and girls and investigated their associations with overweight risk.

Background 

Pediatric obesity is a growing public health concern linked to dietary behaviors and sedentary lifestyles, notably the increased consumption of UPFs among adolescents. UPFs, rich in added sugars, unhealthy fats, and additives but low in essential nutrients, contribute to excessive caloric intake and unfavorable metabolic outcomes.

Sedentary behaviors aggravate this issue and are particularly prevalent in Western countries and Southern Europe.

Precise assessment tools are needed to evaluate UPF consumption and its impact on obesity and well-being in youth, including potential associations with mental health. Further research is necessary to understand these relationships and develop effective interventions.

About the study

A total of 245 adolescents (131 boys and 114 girls), aged 12 to 17 years (mean age 14.20 ± 1.09), were recruited from two randomly selected public high schools in the Coimbra (n = 101) and Viseu (n = 144) districts.

Anthropometric measurements, including height, weight, and body fat percentage using bioelectrical impedance, were collected to calculate body mass index (BMI), which was classified according to International Obesity Task Force guidelines.

UPF consumption was assessed using the NOVA-UPF screener, a questionnaire evaluating UPF intake on the previous day. Sedentary behaviors were self-reported, detailing time spent on activities like watching TV and using electronic devices during weekdays and weekends.

Well-being was measured using the Mental Health Continuum-Short Form and the physical well-being subscale of the KIDSCREEN-27 questionnaire. Parental education levels served as proxies for socioeconomic status.

Statistical analyses included descriptive statistics, t-tests, correlations, and logistic regression, controlling for confounders such as age, sex, sedentary behavior, parental BMI, and education. The study adhered to the Declaration of Helsinki, received ethical approval from relevant authorities, and obtained informed consent from participants and their guardians.

Study results

In the study involving 245 Portuguese adolescents aged 12 to 17 years (mean age 14.2 ± 1.09 years), researchers examined UPF consumption, sedentary behaviors, and well-being, focusing on differences between sexes. The sample comprised 131 boys and 114 girls.

Among the girls, 17.5% were categorized as overweight and 7.9% as obese; among the boys, 15.3% were overweight and 3.1% were obese.

The findings indicated that adolescents consumed similar levels of UPFs across the three food subcategories of the NOVA screener, regardless of whether the consumption was based on a 24-hour recall or occurred outside the home.

During weekdays, the most common sedentary activities were smartphone use, studying, and using a personal computer (PC). On weekends, adolescents reported spending more time using smartphones and PCs, as well as watching television.

No significant differences were observed between boys and girls in UPF consumption across different subcategories. However, girls exhibited higher BMI levels and body fat percentages than boys, with both differences being statistically significant (p < 0.001).

Boys reported higher levels of PC use during weekends (p = 0.025) and spent more time playing electronic games during both weekdays (p = 0.005) and weekends (p < 0.001) compared to girls.

Conversely, girls spent more time studying during weekdays (p = 0.006) and weekends (p = 0.007), and engaged more in activities like board games or reading during weekends (p = 0.026) than boys. Additionally, boys scored higher in all dimensions of well-being (p < 0.001) compared to girls.

Correlation analyses revealed that the 24-hour recall consumption of UPFs, including sugary drinks and yogurts, was positively associated with watching the TV on weekends, playing electronic games, and using weekday smartphones. It was negatively associated with body fat percentage and time spent studying during both weekdays and weekends.

Similarly, the consumption of UPFs like sugary drinks and yogurts outside the home was positively associated with total sedentary time during weekends and negatively associated with body fat percentage and weekend study time.

A similar pattern emerged for the 24-hour recall consumption of packaged and fast food UPFs, which showed positive correlations with weekday television watching and weekend smartphone use and negative correlations with body fat percentage.

The consumption of sweet and salty snack UPFs outside the home was negatively associated with body fat percentage. Importantly, no significant relationships were found between UPF consumption and any dimensions of well-being among the adolescents.

Logistic regression analyses, controlling for variables such as age, sedentary behaviors, sex, parental BMI, and parental education, indicated that UPF consumption tended to be associated with an increased risk of being overweight. However, this association was marginally significant (p = 0.06 to 0.09).

Notably, adolescents whose mothers had higher educational levels were less likely to be classified as overweight or obese (odds ratio = 0.83, 95% CI: 0.70–0.98, p = 0.02). Additionally, increased PC use during weekends was associated with a higher likelihood of being overweight (odds ratio = 0.99, 95% CI: 0.98–1.00, p = 0.04).

Conclusions

To summarize, the study found no gender differences in UPF consumption, mirroring some international findings. Although UPF consumption was marginally associated with a higher risk of being overweight, it was significantly linked to increased sedentary behaviors such as screen time.

Adolescents with mothers who had higher educational levels were less likely to be overweight or obese. No significant associations were observed between UPF consumption and well-being dimensions.

These findings underscore the complex interplay of dietary habits, sedentary behavior, and socio-economic factors in adolescent obesity.