Objectives:The relationship between sleep deprivation and the risk of overweight and obesity is somewhat known in children and adolescents. This study aimed to investigate the relationship between sleep duration and eating snacks in a national sample of children and adolescents aged 6-18 years old. Methods:This cross-sectional study was carried out on the data of the fifth survey of the national school-based surveillance system entitled the "Childhood and Adolescence Surveillance and PreventIon of Adult Non-communicable Disease"(CASPIAN-V) study. Short sleeping duration was defined 10 hr per day for children under 10 years and 9 hr per day for children ≥ 10 years. To assess food habits, the consumption frequency of some food groups including sweets, salty snacks, carbonated beverages, diet soft drinks, soft beer, fresh fruits, dried fruits, fresh juices, vegetables, packed juices, dairy products (milk, yogurt, and cheese), fast foods, tea, sugar along with tea, and coffee was asked using Likert scale ( never, rarely, weekly, and daily).Results: In multivariate model, short sleep versus long sleep in students was associated with increased chance of eating salty snacks (OR = 1.49 [95% CI: 1.38-1.61]; p = .001), soft drinks (OR = 1.12 [95% CI: 1.04-1.20]; p = .002), fast foods (OR = 1.66 [95% CI: 1.54-1.79]; p < .001), tea (OR = 1.49 [95% CI: 1.39-1.61]; p < .001), and tea with sugar (OR = 1.13 [95% CI: 1.05-1.22]; p < .001). In addition, short sleep in students was associated with a decreased odds of daily intake of soft drinks without sugars (OR = 0.64 [95% CI: 0.58-0.70]; p < .001), soft beer (OR = 0.92 [95% CI: 0.85-0.99]; p < .001), fresh fruit (OR = 0.83 [95% CI: 0.76-0.90]; p < .001), dried fruit (OR = 0.43 [95% CI: 0.39-0.46]; p < .001), fresh fruit juice (OR = 0.66 [95% CI: 0.62-0.72]; p < .001), packed juice (OR = 0.91 [95% CI: 0.84-0.98]; p < .009), milk (OR = 0.51 [95% CI: 0.47-0.55]; p < .001), yogurt (OR = 0.86 [95% CI: 0.79-0.93]; p ≤ .001), and coffee (OR = 0.82 [95% CI: 0.76-0.89]; p ≤ .001). Conclusions:The findings of this study indicate a significant relationship between sleep duration and unhealthy food habits. Therefore, increasing awareness of families in this area may reduce obesity and its complications.

Socioeconomic inequality in ST frequency was in favor of low SES groups. These findings are useful for health policies, better programming and future complementary analyses.

Context: Physical environment contamination and in particular, air pollution might cause long-term adverse effects in child growth and a higher risk of catching non-communicable diseases later in life. Objective: This study aimed to overview the human studies on the association of exposure to ambient Particulate Matter (PM) with childhood obesity. Data Sources: We systematically searched human studies published until March 2018 in PubMed, Scopus, Ovid, ISI Web of Science, Cochrane library, and Google Scholar databases. Study Selection: All studies that explored the association between PM exposure and childhood obesity were assessed in the present study, and finally, 5 studies were used in the meta-analysis. Data Extraction: Two independent researchers performed the data extraction procedure and quality assessment of the studies. The papers were qualitatively assessed by STROBE (Strengthening the Reporting of Observational studies in Epidemiology) statement checklist. Results: The pooled analysis of PM exposure was significantly associated with increased Body Mass Index (BMI) (Fisher's z-distribution=0. 028; 95% CI=0. 017, 0. 038) using the fixed effects model. We also used a random-effect model because we found a significant high heterogeneity of the included studies concerning the PM (I 2 =94. 4%; P<0. 001). PM exposure was associated with increased BMI (Fisher's z-distribution=0. 022; 95% CI=-0. 057, 0. 102). However, the overall effect size was not significant, and heterogeneity of the included studies was similar to the fixed effect model. Discussion: Our findings on the significant association between PM10 exposure and the increased BMI (r=0. 034; 95%CI=0. 007, 0. 061) without heterogeneity (I 2 =16. 6%, P=0. 274) (in the studies with PM10) suggest that the PM type might account for the heterogeneity among the studies. Conclusion: The findings indicate that exposure to ambient PM10 might have significant effects on childhood obesity.