title: Bedtime and sleep timing but not sleep duration are associated with eating habits in primary school children.
abstract: OBJECTIVE
  In the context of childhood obesity progression, sleep patterns have been associated with unhealthy eating habits and energy intake. The association between several eating habits and sleep patterns in children has been recently studied. The aim of this study was to explore the association between sleep patterns, eating habits, and physical fitness in primary school children.
  
  
  METHODS
  A total of 236 children of 6 to 10 years old were recruited. Anthropometric characteristics and body composition were measured, and cardiorespiratory (20-m shuttle run test) and musculoskeletal (squat jump and cycling peak power) fitness tests were performed. Parents were asked to fill out an eating habits questionnaire, and children were classified into 4 categories as a function of the number of eating risk factors they presented. Parents completed a questionnaire about their child's bedtime and waking hours during weekdays and weekends.
  
  
  RESULTS
  Weight (p < .01), waist circumference, and fat mass (p < .05) were significantly higher in late sleepers (27.6 ± 6.3 kg; 60.1 ± 7.6 cm; 19.52 ± 7.44) compared with normal sleepers (25.4 ± 3.7 kg; 58.2 ± 4.9 cm; 17.44% ± 6.23%). None of the physical fitness parameters were associated with sleep duration, bedtime, wake-up time, nor were they significantly different between late and normal sleepers. Bedtime was significantly earlier in children consuming breakfast everyday (08:30 vs. 09:00 PM, p < .01); later in children snacking (09:15 vs. 09:30 PM, p < .05) or watching TV at lunch (10:00 vs 09:30 PM, p < .05). There is an association between the proportion of normal and late sleepers and the accumulation of healthy eating habits (p < .001).
  
  
  CONCLUSIONS
  Bedtime and sleep timings (normal or late sleepers) are associated with eating habits in primary school children. It seems necessary to consider the number of unhealthy eating habits adopted by children when studying these associations.
authors.affiliation: *Laboratory of Metabolic Adaptations to Exercise Under Physiological and Pathological Conditions, EA3533, Blaise Pascal University, Clermont University, Clermont-Ferrand, France; †Laboratory Culture Sport Health Society, EA 4660, and Exercise Performance, Health, Innovation Platform, Franche-Comte University, Besançon, France; ‡Université Droit et Santé Lille 2, EA 4488 "Activité Physique, Muscle, Santé," Faculté des Sciences du Sport et de l'Education Physique, Ronchin, France; §Biostatistics Unit (DRCI), Clermont-Ferrand University Hospital, Clermont-Ferrand, France.
authors.forename: David
authors.initials: D
authors.lastname: Thivel
authors.forename: Laurie
authors.initials: L
authors.lastname: Isacco
authors.forename: Julien
authors.initials: J
authors.lastname: Aucouturier
authors.forename: Bruno
authors.initials: B
authors.lastname: Pereira
authors.forename: Nordine
authors.initials: N
authors.lastname: Lazaar
authors.forename: Sébastien
authors.initials: S
authors.lastname: Ratel
authors.forename: Eric
authors.initials: E
authors.lastname: Doré
authors.forename: Pascale
authors.initials: P
authors.lastname: Duché
mesh_terms: D050154:Adiposity; D001835:Body Weight; D002648:Child; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008297:Male; D063766:Pediatric Obesity / Q000209:etiology; D010809:Physical Fitness; D012885:Skinfold Thickness; D012890:Sleep; D011795:Surveys and Questionnaires; D013997:Time Factors; D055105:Waist Circumference