Co-Principal Investigator: Evans, Retta

Purpose: The purpose of this study was to explore the role of diet in middle school students' behavioral and academic outcomes. Although evidence suggests that poor diet quality contributes to emotional and behavioral problems, research examining the temporal relationships between diet, behavior, and academic outcomes had been lacking.

Project Activities: The research team recruited 6th-grade students and followed them annually for 2 years (3 time points). They collected information on students' diet, emotions, behavior, and academic functioning using a combination of global measures and daily reports. They also evaluated each school's nutrition related policies and implementation practices during each annual assessment.

Key Outcomes: The main findings of this exploratory study are as follows:

• Middle school staff and students identified benefits and barriers to implementing school nutrition reforms and providing healthy and palatable meals in school settings. Staff recommended more flexibility in implementation, and students recommended better quality, variety, flavor, and presentation of foods, as well as more comprehensive promotion of healthy eating at school (Evans, Orihuela, & Mrug, 2021; Orihuela, Evans, & Mrug, 2024).
• Students' sociodemographic characteristics and dietary habits are associated with different diversity and composition of the gut microbiome. Specifically, students from suburban and urban areas, racial/ethnic minority students, and students who skip breakfast or eat highly processed and low nutrition quality foods (e.g., processed meats, fried foods, more eating out) have less diverse and less healthy guts that may contribute to more health problems over time (Kemp, Orihuela, Morrow, Judd, Evans, & Mrug, 2024).
• Food insecurity, defined as limited access to adequate foods due to a lack of money or resources, contributes to lower academic skills over time in middle school students over and above household income and other sociodemographic characteristics. Reducing food insecurity through school nutrition and other public policy programs is important to support students' academic outcomes (Orihuela, Cox, Evans, & Mrug, 2023).
• Sleep plays a key role in middle school students' academic enablers, academic skills, and grades. Students who sleep about 8 hours per night and who do not feel sleepy during the day have better academic outcomes than those who sleep fewer than 7 hours or more than 9 hours per night and those who feel sleepy during the day (Orihuela, Evans, & Mrug, 2023).
• Middle school students who experience more stress feel more anxious and depressed. Students who have more conflict with teachers engage in more aggressive and rule breaking behaviors, whereas those with positive student-teacher relationships behave less aggressively over time. Interventions that promote stress management and positive student-teacher relationships may improve students' adjustment at school (Keane, Evans, Orihuela, & Mrug, 2023).

Structured Abstract

Setting: This study took place in urban, suburban, and rural school districts in Alabama.

Sample: Across 14 public middle schools and 1 private school, 288 students participated in this study. Students came from socioeconomically diverse backgrounds. Of the participants, 50 percent were Black and 10 percent were Hispanic.

Factors: Researchers investigated students' dietary quality, emotions, behavior, and academic functioning as well as each school's nutrition policies and implementation practices.

Research Design and Methods: Students participating in the study completed a week-long assessment once a year beginning in 6th grade and at the 1-year (7th grade) and 2-year (8th grade) follow ups. Each assessment consisted of completing global measures and five daily reports of diet, behavior, emotions, and academic functioning. The researchers collected additional information on these constructs from parents and teachers, observations, and school records. Finally, the researchers evaluated nutrition related policies and practices at each participating school through review of documents, interviews with key informants, and objective assessments. They tested relationships between students' diet, behavior, and academic functioning and clarified how these relationships unfolded over time.

Control Condition: Due to the exploratory nature of the research design, there was no control condition.

Key Measures: The researchers asked students, teachers, and parents to complete global or daily measures of diet and emotional, behavioral, and academic functioning. The global measures included student, parent, and teacher reports; observations and objective assessments by researchers; and school records. Daily measures included student reports and observations. At the school level, nutrition related policies and practices were evaluated through review of documents, interviews with key informants, and observations.

Data Analytic Strategy: The researchers used regression models to test the relationships between diet, behavioral and emotional functioning, and academic outcomes cross-sectionally and over time. They used descriptive statistics to characterize school-based nutrition policies and practices and their variation between and within school districts.

Products and Publications

ERIC Citations: Find available citations in ERIC for this award here.

Select Publications:

Doolittle, E. (2019, September 19). Are You What You Eat? Understanding the Links Between Diet, Behavior, and Achievement During Middle School. Inside IES Research.

Evans, R. R., Orihuela, C. A., & Mrug, S. (2021). Middle school stakeholder perceptions of school nutrition reform since the Healthy, Hunger-free Kids Act of 2010. American Journal of Health Education, 52(5): 276–287. DOI: 10.1080/19325037.2021.1955226

Keane, K., Evans, R. R., Orihuela, C.A., & Mrug, S. (2023). Teacher-student relationships, stress, and psychosocial functioning during early adolescence. Psychology in the Schools, 60: 5124–5144.

Kemp, K., Orihuela, C.A., Morrow, C. D., Judd, S. E., Evans, R.R., Mrug, S. (2024). Associations between dietary habits, socio-demographics, and gut microbial composition in healthy adolescents. British Journal of Nutrition. 131(5):809–820.

Lin, Y. C., Gallo, S., Baxter, S., Orihuela, C., Xu, J., Chen, X., Mrug, S. & Evans, R. (2022). PO84 The Relationship between middle-School children's body mass index, school lunch participation and consumption. Journal of Nutrition Education and Behavior, 54(7), S57.

Orihuela, C.A., Evans, R.R., Mrug, S. (2024). Student stakeholders' perspective on middle school lunch programs: A qualitative study. American Journal of Health Education. DOI: 10.1080/19325037.2023.2297286

Orihuela, C., Cox, C., Evans, R. R., & Mrug, g, S. (2023). Associations of household food insecurity with academic outcomes in early adolescents. Journal of School Health, 93(10): 883–890.

Orihuela, C., Evans, R. R., & Mrug, S. (2023). Associations between sleepiness, sleep duration and academic outcomes in early adolescence. Psychology in the Schools, 60(6): 1936–1957.