Higher Baseline Diet Quality Is Positively Associated With Academic and Physical Performance Among United States...

Service Academy Cadets are exposed to physical and cognitive stressors including a rigorous schedule composed of academic, athletic, physical, and military training requirements, along with chronic sleep restriction, during and across semesters. Although research has examined stress-sleep relationships in military personnel and college students, the interrelationships between stress, sleep, and dietary quality among service academy cadets requires further study to inform interventions that optimize health and performance. This secondary analysis of a prospective cohort study examined interrelationships between stress, sleep, and dietary quality among cadets' in the setting of academic and athletic rigor.

United States Military Academy (USMA) cadets (n = 268; age = 20 ± 2 years; body mass index [BMI] = 25.2 ± 2.7 kg/m2) completed baseline (BL, approximately 1 month into the Fall semester) and follow-up (POST, ∼12 days before final December exams) measures including the Perceived Stress Scale (PSS), Pittsburgh Sleep Quality Index (PSQI), and VioScreen food frequency questionnaire. Diet quality was evaluated using the Healthy Eating Index-2020 (HEI-2020). Academic, military, and physical performance were assessed using final semester scores and Army Combat Fitness Test (ACFT) scores.

Perceived stress scale scores indicated moderate stress levels that significantly decreased from BL to POST [(mean ± SD): 22.7 ± 7.0 to 20.8 ± 7.4, respectively, P < .001]. Pittsburgh Sleep Quality Index scores indicated poor sleep quality at both timepoints but showed modest improvement over time (6.2 ± 2.4 to 6.0 ± 2.3, respectively, P < .001). Significant positive correlations were observed between PSS and PSQI scores at PRE (r = 0.36, P < .001) and POST (r = 0.46, P < .001), indicating that reduced stress was associated with improved sleep quality. Total HEI scores fell in the "needs improvement" range, declined from PRE (60.8 ± 9.5) to POST (58.4 ± 10.3, P < .001), and were not correlated with stress or sleep measures. Higher diet quality at baseline was associated with higher academic scores at the end of the term (B = 0.01 ± 0.01, P = .004), physical scores at the end of the term (B = 0.01 ± 0.01, P = .018), and ACFT scores at the beginning of the term (B = 0.98 ± 0.24, P < .0001).

This study revealed suboptimal diet quality among USMA cadets throughout the academic semester. Higher diet quality at baseline was associated with higher academic and physical scores at the end of the term. Significant associations between reduced stress and improved sleep quality were noted, however both measures remained within suboptimal ranges indicating persistent moderate stress and poor sleep quality in this population. The findings demonstrated connections between diet quality with academic and physical performance, and support the continued implementation and evaluation of targeted nutritional strategies for increasing consumption of nutritious foods, especially given that Cadets are consuming most meals in a dining facility where food choice may be constrained.