sleep habits and dietary intake among preschool children in qazvin

background sleep habits and total sleep duration are essential factors for healthy growth and development of children. there is evidence showing that eating time and quantity as well as proportion of foods macronutrients affect the sleep quality. objectives the aim of this study was to investigate the sleep habits of preschool children in qazvin and the role of calorie, macronutrients and caffeine intake in a mixed normal meal on sleep induction. materials and methods a total number of 210 children of 3 - 6 years old (108 boys and 102 girls) were randomly selected from a pediatric clinic in the city of qazvin. participants’ heights and their weights were recorded using standard techniques. sleep habits questionnaires were filled out and three 24-hour diet-recalls for one weekend and two weekdays were assigned by a trained health worker. results the total night sleep duration, bedtime and wake-up time in the morning were 10.30 ± 1.30 hours, 23.30 ± 1.30 pm and 9.0 ± 1.30 am, respectively. among all children, 21.9% had sleep onset latency and the bedtime of 56% was 10 pm or later. the results of this study showed no significant relationship between calorie, macronutrients, and caffeine intakes of the children, and the total sleep duration, bedtime, wake-up time, and sleep latency (p > 0.05). conclusions based on the results of this study, no significant relationship was observed between the dietary intake and sleep habits. this might be due to the small sample size or other factors, suggested to be investigated in the future.