Associations of diarised sleep onset time, period and duration with total and central adiposity in a biethnic sample of young children: the Born in Bradford study

Abstract

Objectives: To investigate associations of sleep timing, period and duration with total and abdominal adiposity in a biethnic sample of children aged 18 and 36 months (m) Design: Cross-sectional observational study Setting: The Born in Bradford 1000 study, UK Participants: Children aged approximately 18m (n=209; 40.2% South Asian; 59.8% White) and 36m (n=162; 40.7% South Asian; 59.3% White) Primary and secondary outcome measures: Parents completed a 3-day sleep diary from which children's average daily sleep onset time, period and duration were calculated. Weekday to weekend differences in sleep parameters were also derived. As outcomes, indices of total (BMI z-score and sum of 2-skinfolds) and abdominal adiposity (waist circumference) were measured. Adjusted regression was used to quantify associations of sleep parameters with adiposity by age group and ethnicity. Results: The average daily sleep onset time was markedly later in South Asian (9:26pm ± 68 mins) than White children (7:41pm ± 48 mins). Later sleep onset was associated with lower BMI z-score and sum of 2-skinfolds in White children aged 18m. In contrast, later sleep onset was associated with higher BMI z-score in South Asian children aged 36m. For weekday to weekend differences, longer sleep duration and later sleep onset on weekends than weekdays were both associated with higher total and abdominal adiposity in South Asian children aged 18m. On the contrary, compared to consistent sleep onset times, going to sleep ≥20 minutes later on weekends than weekdays was associated with lower waist circumference in White children aged 18m. Conclusions: Sleep timing is associated with total and central adiposity in young children but associations differ by age group and ethnicity. Sleep onset times and regular sleep schedules may be important for obesity prevention.

Independent associations of sleep timing, duration and quality with adiposity and weight status in a national sample of adolescents: The UK Millennium Cohort Study

“…Furthermore, it is a limitation that information was not available for potentially key mediating variables, such as unhealthy snacking and meal times. Sleep restriction studies report increased snacking under short sleep conditions, particularly when participants would normally be asleep (Beebe et al, 2013; Nedeltcheva et al, 2009), and an investigation of young children found that an association of later sleep onset with higher adiposity was attenuated when adjusted for timing of the evening meal (Collings et al, 2021). Animal models and clinical trials of adult populations indicate that early and time‐restricted feeding has numerous physiological benefits, including lower adiposity (de Cabo & Mattson, 2019; Sutton et al, 2018).…”

Independent associations of sleep timing, duration and quality with adiposity and weight status in a national sample of adolescents: the UK Millennium Cohort Study

“…Furthermore, it is a limitation that information was not available for potentially key mediating variables such as unhealthy snacking and meal times. Sleep restriction studies report increased snacking under short sleep conditions, particularly when participants would normally be asleep [35, 36], and an investigation of young children found that an association of later sleep onset with higher adiposity was attenuated when adjusted for timing of the evening meal [37]. Animal models and clinical trials of adult populations have further shown that early and time-restricted feeding has numerous physiological benefits, including lower adiposity [38, 39].…”