Longitudinal and Bidirectional Relationships Between Sleep, Emotional Wellbeing and Weight Status in Childhood and Adolescence: Growing Up in Scotland Cohort Analysis

Poor sleep and emotional wellbeing, which often decline during puberty, are associated with declines in metabolic health and are key determinants of childhood obesity. The aim of the study was to explore bidirectional associations between sleep, emotional wellbeing and obesity from ages 8 to 14 using the Growing Up in Scotland cohort. Secondary analyses were conducted on data from sweeps 7-10 (ages 8-14). Sleep duration was caregiver-reported at age 8 and self-reported at 14. Obesity was assessed using BMI percentiles (BMIp), derived from objective height and weight at ages 8, 10, 12 and 14. Emotional wellbeing was assessed using the Strengths and Difficulties Questionnaire caregiver-report at 10 and 12 years, and self-report at 14 years. Pearson correlations and adjusted regressions examined associations between sleep, BMIp and emotional wellbeing from ages 8 to 14. Analyses included 4157 participants (50.2% male). Shorter sleep at 8 years was associated with higher BMIp at 12 years (β = -0.172, CI (95%) = -0.335, -0.116, p < 0.001) and poorer emotional wellbeing at 10 (β = -0.120, CI (95%) = -0.179, -0.034, p < 0.001) and 12 years (β = -0.101, CI (95%) = -0.164, -0.026, p < 0.001). Poorer emotional wellbeing at 10 (β = -0.116, CI (95%) = -0.232, -0.093, p < 0.001) and 12 years (β = -0.194, CI (95%) = -0.328, -0.174, p < 0.001) predicted shorter sleep at 14 years. Higher BMIp at 8 years was associated with shorter sleep at 14 years (β = -0.182, CI (95%) = -0.359, -0.111, p < 0.001). Poorer emotional wellbeing at 10 years was associated with higher BMIp at 14 years (β = 0.142, CI (95%) = 0.074, 0.629, p = 0.13). Bidirectional associations emerged between short sleep and emotional wellbeing and higher BMIp. Poor emotional wellbeing was associated with subsequent obesity; but not bidirectionally. These interactions should inform the design of health interventions for 8-14-year-olds.