Bedtime and Sleep Timing but not Sleep Duration Are Associated With Eating Habits in Primary School Children

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 6 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). Conclusion: 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.