Tehran University of Medical Sciences Journal of Nutritional Sciences and Dietetics 2 5 2017 08 01 88 88 EN Azimeh Izadi PhD Candidate, Department of Biochemistry and Diet Therapy, Nutrition Research Center, Faculty of Nutrition and Food Science, Tabriz University of Medical Sciences, Tabriz, Iran AND Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran Reza Daryabeygi-Khotbesara MSc, Department of Clinical Nutrition, Tehran University of Medical Sciences, Tehran, Iran Fereshteh Aliasghari PhD Candidate, Department of Biochemistry and Diet Therapy, Nutrition Research Center, Faculty of Nutrition and Food Science, Tabriz University of Medical Sciences, Tabriz, Iran AND Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran Kourosh Djafarian PhD, Department of Clinical Nutrition, Tehran University of Medical Sciences, Tehran, Iran 2017 06 06 2017 08 01 Objectives: Obesity is a multifactorial condition showing a rapid rise worldwide, especially in children and adolescents. The present study aims to investigate the impact of sleep duration, TV watching, and dietary intake on the risk of childhood obesity. Subjects and methods: A cross-sectional study was undertaken among 270 primary school children in Tehran, Iran. Sleep duration was measured using an ActiGraph device worn on the wrist. Using a questionnaire completed by parents, screen time (TV, video games, etc.) was estimated. Also, weight, height, and body mass index (BMI) were obtained. Data were analyzed with SPSS software (version 18, IBM Corporation). Conclusion: Screen time is significantly associated with BMI, diet, and sleepin Iranian school children. Further studies are required to elaborate these associations. Results: Lower BMI and longer sleep duration were associated with less screen time (p < 0.01). Higher daily energy (1673.4 ± 405.3 kcal), total fat (55.3 ± 19.3 g),carbohydrate (238.5 ± 67.1 g), sugars (114.3 ± 34.9 g), and snack (37.4 ± 19.3 g)consumption as well as lower daily fiber (7.9 ± 3.7 g) and vegetable and fruit (2.6 ±1.3 servings) intakes were significantly correlated with longer screen time in children (p < 0.05). Lower fiber (8.1 ± 4.2 g) as well as fruit and vegetable (2.6 ±1.4 servings) consumption were related to longer sleep duration (≥ 540 min/day) (p< 0.01 https://jnsd.tums.ac.ir/index.php/jnsd/article/view/88 https://jnsd.tums.ac.ir/index.php/jnsd/article/download/88/152