Association between sleep duration and overweight: the importance of parenting

International Journal of Obesity (2012) 36, 1278–1284 & 2012 Macmillan Publishers Limited All rights reserved 0307-0565/12 www.nature.com/ijo PEDIATRIC ORIGINAL ARTICLE Association between sleep duration and overweight: the importance of parenting E de Jong1,2, T Stocks3,4, TLS Visscher1,2, RA HiraSing5, JC Seidell1,2 and CM Renders1,2 OBJECTIVE: Sleep duration has been related to overweight in children, but determinants of sleep duration are unclear. The aims were to investigate the association between sleep duration and childhood overweight adjusted for family characteristics and unhealthy behaviours, to explore determinants of sleep duration and to determine with sleep competing activities. METHOD: A cross-sectional study was carried out in 2006 among 4072 children aged 4–13 years in the city of Zwolle, The Netherlands. In these children, data were available on measured height, weight and waist circumference, and from a parental questionnaire, on socio-demographic characteristics, child’s sleep duration, nutrition, physical activity and sedentary behaviour. Associations were studied in 2011 using logistic and linear regression analyses, adjusted for potential confounders. RESULTS: Short sleep duration was associated with overweight for 4–8-year-old boys (odds ratio (OR):3.10; 95% confidence interval (CI):1.15–8.40), 9–13-year-old boys (OR:4.96; 95% CI:1.35–18.16) and 9–13-year-old girls (OR:4.86; 95% CI:1.59–14.88). Among 4–8-year-old girls no statistically significant association was found. Determinants for short sleep duration were viewing television during a meal, permission to have candy without asking, not being active with their caregiver and a late bedtime. For all children, short sleep duration was strongly associated with more television viewing and computer use. CONCLUSIONS: Association between sleep duration and overweight is not explained by socio-demographic variables, drinking sugared drinks and eating snacks. Parents have a key role in stimulating optimal sleep duration. Improving parenting skills and knowledge to offer children more structure, and possibly with that, increase sleeping hours, may be promising in prevention of overweight. International Journal of Obesity (2012) 36, 1278–1284; doi:10.1038/ijo.2012.119; published online 24 July 2012 Keywords: childhood overweight; sleep; parenting; home environment; healthy lifestyle; prevention INTRODUCTION Over the past decades, there has been a growing interest in the relationship between sleep duration and high body weight. A large number of studies has shown an association between reduced sleep duration and childhood overweight, especially in young children.1–3 The association between short sleep duration and overweight seems to be stronger for boys than girls,4 although not all studies have reported a gender difference.2 Possible explanations for the association between sleep duration and overweight include the role of behavioural and hormonal factors; short sleep leaves more time for eating, particularly snacking or drinking sugared drinks, and causes alterations in appetite-regulating hormones resulting in overeating.1,2,5 Moreover, sleepiness may result in reduced physical activity and increased sedentary behaviour.1,2,5 Determinants of short sleep duration have not yet been fully explored. Presumably, sleep duration is influenced by a combination of socio-demographic, behavioural and environmental factors. With regard to socio-demographic factors, children of Caucasian ethnicity have been indicated to sleep longer than children of other ethnicities.6–9 Age is inversely associated with sleep deprivation.10 The role of environmental factors on sleep duration is unclear, but there are indications that the physical and socio-cultural home environment play an important role.3,11 A recent study among children aged 8–11 years suggested that less structure and rules in the home environment is associated with less sleep and more unhealthy behaviour, which is also associated with overweight.11 It remains unclear whether the association between such family characteristics and unhealthy behaviours explain the association between sleep duration and overweight, or whether sleep duration and overweight are also associated independently. This is important information to learn whether overweight prevention should target sleep duration per se and/or the determinants and behaviours that are associated with sleep duration. Before starting developing interventions to increase sleeping time, it is also important to know what the competing activities are for sleeping. Some studies indicate that shorter sleep duration is associated with more television viewing and computer use;12–15 others found a relation between physical activity and sleep duration in girls, only.12 However, these results are inconsistent.14,16,17 1 Research Centre for the Prevention of Overweight, VU University Amsterdam/Windesheim University of Applied Sciences, Zwolle, The Netherlands; 2Department of Health Sciences, Faculty of Earth and Life Sciences and EMGO Institute for Health and Care Research, VU University Amsterdam, Amsterdam, The Netherlands; 3Department of Surgical and Perioperative Sciences, Urology and Andrology, Umeå University, Umeå, Sweden; 4Institute of Preventive Medicine, Copenhagen University Hospitals, Copenhagen, Denmark and 5Department of Public and Occupational Health, EMGO Institute for Health and Care Research, VU University Medical Centre, Amsterdam, The Netherlands. Correspondence: E de Jong, Research Centre for the Prevention of Overweight, VU University Amsterdam/Windesheim University of Applied Sciences, PO box 10090, Zwolle, Overijssel 8000 GB, The Netherlands. E-mail: Received 20 December 2011; revised 28 May 2012; accepted 18 June 2012; published online 24 July 2012 Sleep duration associated with childhood overweight E de Jong et al 1279 The aims of this study are as follows: (1) To investigate the association between sleep duration and childhood overweight adjusted for family characteristics and unhealthy behaviours. (2) To explore determinants of sleep duration in the home environment. (3) To determine what the competing activities are with sleeping in these children. MATERIALS AND METHODS Study population Data collected in the ChecKid 2006 study have been used for this study. ChecKid is a cross-sectional study carried out among children of primary schools (4–13 years) within 3 weeks in October and November 2006 in the city of Zwolle. This study was aimed at identifying neighbourhoods/ communities at high risk for overweight, other high-risk groups and behaviours related to overweight in the city of Zwolle to develop and implement an integrated approach to tackle overweight in children. Details on the study population and data collection have been described elsewhere.18 All 51 primary schools in the city were invited to participate and 80% of the schools (n ¼ 41) agreed to participate. Number of students (...truncated)