Pro-Inflammatory Dietary Profiles Are Associated with Psychosocial Functioning in Spanish Adolescents: Findings from the EHDLA Study.

Background: Dietary factors may influence psychosocial outcomes through inflammatory pathways, but evidence in adolescents remains limited. The aim was to examine whether dietary inflammatory potential is associated with psychosocial functioning among Spanish adolescents. Methods: This cross-sectional study is based on a subsample from the Eating Healthy and Daily Life Activities (EHDLA) project, conducted in the Region of Murcia (Spain). Dietary inflammatory potential was assessed using a dietary inflammatory index (DII)-informed Food Frequency Questionnaire (FFQ)-derived inflammatory score based on a validated 45-item food frequency questionnaire. Behavioral functioning was evaluated using the Strengths and Difficulties Questionnaire (SDQ). Associations between DII-informed FFQ-derived inflammatory scores and SDQ outcomes were examined using robust linear regression models adjusted for sociodemographic, lifestyle, and anthropometric factors. Results: The analysis included 674 adolescents (57.1% girls; age: 14.0 [13.0-15.0] years). Higher DII-informed FFQ-derived inflammatory score (more pro-inflammatory diet) was associated with greater total behavioral difficulties (unstandardized beta coefficient [B] = 0.058; 95% confidence interval [CI]: 0.005-0.111; standardized β = 0.099), conduct problems (B = 0.025; 95% CI: 0.011-0.039; β = 0.148), hyperactivity/inattention (B = 0.032; 95% CI: 0.013-0.052; β = 0.154), and externalizing problems (B = 0.056; 95% CI: 0.028-0.084; β = 0.181), and with lower prosocial behavior (B = -0.029; 95% CI: -0.045 to -0.014; β = -0.149). Multiple imputation sensitivity analyses yielded estimates in a similar direction, although the associations did not reach statistical significance. No significant associations were observed for emotional symptoms, peer relationship problems, or internalizing difficulties. Conclusions: Higher dietary inflammatory potential was associated with a less favorable psychosocial functioning profile among adolescents, particularly in externalizing domains. Longitudinal studies and anti-inflammatory dietary interventions are needed to determine whether the observed associations translate into meaningful changes in psychosocial functioning.