Health literacy was identified as an important determinant of health, particularly for adolescents. However, more efforts are needed to monitor this construct and provide inputs for policy development. This study aims to: (a) Assess the validity and reliability of the Italian version of the Health Literacy for School-Aged Children (HLSAC-I); (b) Identify the health literacy levels among Italian students and compare them with other countries’ levels; and (c) Identify the associations between health literacy and multiple social determinants (social stratifiers, family, and school connectedness). Data came from the Health Behaviour School-Aged Children survey, carried out in the Lombardy region in northern Italy in 2018. A representative sample of 2,287 13- and 15-year-old Lombardian students was involved. The results support the validity and reliability of the HLSAC-I. A total of 18.7% of the sample reported low levels, and only 6.8% reported high levels. Italian students reported the lowest levels of health literacy compared with other countries. School connectedness and educational approach are the most relevant associated factors. This study confirms a school’s role in reducing inequalities and promoting health. It highlights the importance of monitoring health literacy and implementing health promotion policies at school through a whole-school approach.

Background Health behaviours in adolescence have a high impact on both current and future health. The literature claims a focus on social determinants and shows that these behaviours are associated. The concept of ‘health lifestyles’ should be considered to account for co-occurring health behaviours and determinants interactions. The aim of this study is to increase our understanding of adolescents’ health lifestyles and to (i) cluster adolescents according to a comprehensive number of health behaviours and (ii) describe these groups according to sociodemographic characteristics, perceptions of life contexts (family, school, peers or neighbourhood) and perceived physical and psychosocial health conditions. Methods In Italy, 906 15-year-old students participated in the cross-national Health Behaviour of School-aged Children study. Clusters were identified by applying the KAMILA clustering method and compared using analysis of variance and chi-squared tests. Results: Four clusters were identified: ‘substance consumers’, ‘media lovers’, ‘active students’ and ‘passive students’. Each cluster exhibited different characteristics related to health behaviours and social determinants. Conclusions Interesting associations between health behaviours were identified, which showed the relevance of considering the adolescents’ overall lifestyles. The description of each cluster permitted the identification of risks and protective factors, which may be important for designing effective health promotion activities.