Association between individual and environmental factors with body mass index for age z-score in female adolescents living in North-West of Iran

Purpose The purpose of this study was to investigate the association of individual and environmental indicators with body mass-index-for-age-z-score (BAZ) of female adolescents living in the North-West of Iran. Design/methodology/approach In this cross-sectional study, 380 female adolescents aged 16-18 years were selected from two major ethnic groups (Azeri and Kurd) in Urmia city selected by stratified cluster sampling method. In total, 13 high schools (9 public and 4 private) were selected across all municipality zones of Urmia city. BAZ was calculated by Anthro-Plus software. Demographic and socioeconomic information of samples were collected by a questionnaire through interviews. Home environment features (including physical activity facilities, television, computer games and social media use, food consumption habits and family rules) and school environment features (including socioeconomic status [SES], physical activity facilities, food consumption habits) were evaluated by two separate self-constructed questionnaires via an interview with adolescents and schools’ deans, respectively. Findings Azeri adolescents had parents with higher education and job level and higher SES compared to Kurds (p = 0.000). A higher percent of Azeri adolescents were obese than their Kurd counterparts (p = 0.006). No association was found between individual factors and BAZ in each ethnic group. Considering home environment characteristics, in Kurd adolescents, the maternal occupational level was positively associated with BAZ (p = 0.02). With regard to school environmental features, accessibility of physical activity facilities in school was inversely associated with BAZ only in Kurds (p = 0.005). Originality/value To the best of the authors’ knowledge, this is the first study to investigate various environmental factors in association with adolescent’s overweight/obesity prevalence in different ethnical groups in northwest Iran.