Trajectory and trend of weight status, emotional wellbeing and sleep from infancy to childhood to adolescence in Scotland: an analysis of growing up in Scotland birth cohort 1

Background: Childhood obesity interventions often overlook sleep and emotional wellbeing, though research shows both are associated with weight status across childhood. The timing of their co-development and the most effective point for intervention remain poorly understood. The aim of this study was to examine the trajectories of sleep, weight status and emotional wellbeing using the Growing Up in Scotland birth cohort 1 dataset.

Methods: This study conducted secondary data analyses from sweeps 1–10 (10 months-14 years). Sleep was assessed through main-carer and self-reports, covering duration, bedtime, fragmentation, insomnia symptoms and oversleeping. Weight status was evaluated using BMI percentiles from objective height and weight measurements. Emotional wellbeing was evaluated using the emotional symptoms subscale of the Strengths and Difficulties Questionnaire. Trajectories were categorised as stable, improving, or declining for wellbeing; stable, obesogenic or leptogenic for weight; and compared against age-specific recommendations for sleep.

Results: Analyses from 4157 participants (50.2% male) showed that sleep duration declined with age, falling significantly below age-specific recommendations between 8 and 14 years. Bedtimes became later and more variable between 8 and 10 years, with insomnia symptoms and delayed sleep onset common by age 14. Obesogenic or fluctuating weight trajectories were observed in 51.2% of participants. Emotional wellbeing declined notably between 10 and 14 years.

Conclusions: Declines in sleep and emotional wellbeing coincided with rising obesity rates between ages 10 and 12. Targeted intervention between ages 8 and 10 years offers a critical opportunity to mitigate risks of obesity, poor sleep and declining emotional wellbeing before adolescence.