NUTRITIONAL STATUS AND COFACTORS IN ADOLESCENTS: EVIDENCE FROM AN ITALIAN MULTICENTRIC COHORT

Adolescence represents a developmental period characterized by rapid physical growth, hormonal changes, and evolving dietary behaviors, with an impact on the establishment of dietary habits that influence health trajectories into adulthood. Understanding the multifaced determinants of nutritional status in this vulnerable population is essential for developing targeted interventions for health promotion. Herein, an integrated evaluation of the nutritional status of Italian adolescents is conducted through: (1) the analysis of Mediterranean Diet (MD) adherence patterns across different Italian geographic areas; (2) the assessment of factors associated with MD adherence and with a normal-weight status; (3) the investigation of adolescents’ nutrition knowledge (NK), including the development and validation of a sustainability-related nutrition knowledge questionnaire (SUNK-A); and (4) the exploration of salivary fatty acids as non-invasive nutritional biomarkers. A narrative review confirmed that MD adherence among Italian adolescents is generally suboptimal, with low adherence affecting approximately one third of individuals and higher prevalence observed in Southern regions. Weight status emerged as the most consistently associated factor across studies. The multicentric observational SUN_ITA study involved 475 adolescents (mean age 12.7 ± 0.9 years; 44.8% females) from Milan, Rome, and Naples. Normal weight was the most prevalent condition (57.4%), while overweight and obesity were more frequent in Rome than in Milan (p = 0.003). MD adherence was predominantly moderate and comparable across cities and urban areas. However, boys showed significantly higher adherence than girls (p = 0.001). After adjustment, a multivariate logistic regression analysis highlighted that MD adherence was not independently associated with overweight/obesity, whereas male sex (OR = 2.01, p = 0.004) and city of residence (Rome vs. Milan: OR = 1.91, p = 0.006) were identified as significant predictors. Nutritional knowledge (NK) was explored as a determinant of adolescents’ dietary habits, with the development of a questionnaire specifically focused on NK in the context of sustainability; it demonstrated acceptable internal consistency (Cronbach’s α = 0.73). Adolescents’ NK, particularly sustainability-related NK, was positively associated with MD adherence (p < 0.001), but not with BMI-based indicators, although associations with selected body composition parameters were observed. Parental NK showed an indirect association with adolescents’ NK (p = 0.032). Pilot studies on salivary fatty acids revealed limited concordance with blood matrices but suggested potential associations with dietary intake and body composition, supporting their future investigation as non-invasive biomarkers. This research provides novel insights into the nutritional status of Italian adolescents across different geographic regions and social contexts. Overall, the findings highlight the importance of adopting an integrated and context-sensitive approach to nutrition education during adolescence, acknowledging the interplay between individual, familial, and environmental determinants of nutritional status. Furthermore, the results support the need for future research to expand the investigation of non-invasive biomarkers, such as salivary fatty acids, and to implement longitudinal study designs to more effectively capture the dynamic relationships between dietary behaviors, growth trajectories, and health outcomes throughout adolescence.