Ultra-Processed Foods Linked to Mental Health Issues in Teens

New research revealed that adolescents who consume high amounts of ultra-processed food may have higher rates of depressive symptoms and tend to internalize their problems more than those who have a lower "junk" food intake.

Previous reports suggest that consuming ultra-processed food may increase the risk of cancer, and food additives found in some types of processed meats may raise the risk of type 2 diabetes.

But not much is known about whether a diet high in ultra-processed foods impacts mental health, particularly the mental wellbeing of teenagers.

Recently, researchers from the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB) and the Girona Biomedical Research Institute (IDIBGI) decided to take a closer look at potential links between ultra-processed foods and mental health among adolescents.

Between February and April 2022, scientists examined ultra-processed food consumption and psychosocial functioning in 560 Spanish teenagers ages 14 to 17.

The adolescents completed questionnaires about their age, sex, physical activity levels, ultra-processed food consumption in the previous day, and fruit and vegetable intake. The teens also completed the Pediatric Symptom Checklist–Youth self-report to assess psychosocial functioning.

The participants reported an average intake of 7.72 servings of ultra-processed food a day, with over 50% reporting they consumed cold and processed meats and cookies. However, male teens had a higher consumption of junk foods than females.

The scientists also found that fruit and vegetable consumption and physical activity levels were lower than experts recommend. However, female teenagers reported eating more fruits and vegetables than males, while male adolescents reported engaging in more physical activity. Still, only 10% of the participants met the established recommendations of 7 days of physical activity per week.

The research team discovered that 26.2% of the participants had psychosocial impairment. Among these teens, 33.9% had emotional distress — mainly linked to depression or anxiety, 9.5% experienced difficulty with attention, and 3.9% exhibited behavioral challenges.

When the scientists compared ultra-processed food intake with psychosocial functioning results, they found that participants who ate more junk food had a higher rate of depressive symptoms and internalizing and externalizing their problems.

Although female teens reported more depressive symptoms, anxiety symptoms, and internalizing problems overall, after conducting sex-stratified analyses, the scientists found that the associations between junk food consumption and mental health concerns were stronger in male teenagers.

The study authors say these findings support similar studies previously conducted in Brazilian adolescents.

Why male teens seem more affected by high consumption of ultra-processed food than females remains unclear. However, scientists think differences in brain development between males and females may be a possible reason. In addition, some types of junk food, like processed meats and energy drinks, have been linked to a higher risk of depressive symptoms.

Though the study revealed an association between high consumption of ultra-processed foods and mental health concerns in teenagers, it did have some limitations. Specifically, the participants self-reported their dietary intake, exercise, and psychosocial functioning, which could impact the results. Also, the study did not include information on other variables associated with mental health concerns, such as educational level, smoking, or prior stressful life events.

Still, because the results support previous findings, the study authors say that more research is needed to examine the impact of long-term ultra-processed food consumption on teens’ mental health and wellbeing.