Is the association of weight disorders with perceived health status and life satisfaction independent of physical activity in children and adolescents? The CASPIAN-IV Study.

Background: Physical activity (PA) and weight status have been suggested as predictors of life satisfaction (LS) and perceived health status (PHS). Therefore the present study aims to investigate and compare the impacts of body mass index (BMI) and PA on LS and PHS in a population of Iranian children and adolescents. Material and Methods: This study was conducted in 2011-12 as a nationwide population-based study among 14 880 students of age 6-18 years. Students were selected via a multistage cluster sampling method from 30 provinces of Iran. Information on demographics, PA, PHS and LS was obtained using the World Health Organization Global School-based Student Health Survey (WHO-GSHS) questionnaire. PA values were considered as low (<2/week), moderate (2-4 h/week) and high (>2 h/week). Results: The current study has a participation rate of 90.6% (50.8% boys). PA was significantly associated with both LS and PHS [odds ratio (OR), 1.37 in both), while in BMI, this association was significant for only PHS (in underweight: OR, 0.65; 95% CI, 0.57-0.75; in excess weight: OR, 0.82; 95% CI, 0.73-0.93). In the combined group of BMI-PA, the influence of PA prevailed over the impact of BMI on PHS and LS, and therefore, PA was found to be the stronger factor. Conclusion: Although BMI and PA could both significantly impact LS and PHS, the stronger influence of PA on LS and PHS suggests that upgrading the 'activity level' of children and adolescents should be underscored and included on the agenda, rather than merely focusing on their BMI and weight status.